I made a short comparison about the cost, effort and benefits of lying about the shape of the Earth
NASA:
1) The number and details of sources supporting a spherical Earth.
For a spherical Earth you find thousands of sources from many different people from all over the world. Many of which are in great detail.
2) Explanations for many phenomena about Earth the universe and so on.
Science tries to explain everything. If you ask scientists a question, the try to find the best fitting answer. Also all their answers are supported by evidence, calculations and so on. In case that they find contradictions (which happens frequently), they look into it, look for mistakes in their model and update it. With a bit of research you can find a paper for pretty much anything in great detail.
3) Photos from space.
I know you don't believe in neither space travel nor photos. Still there are tens of thousands. NASA alone has more than 28,000 photos and videos about Earth.
https://images.nasa.gov/search-results?q=earth&page=1&media=image,video&yearStart=1920&yearEnd=2018Before you try to prove the photos to be fake, read the description. For example:
https://images.nasa.gov/details-PIA18033.htmlNASA clearly states that this photo is a montage.
Behold one of the more detailed images of the Earth yet created. This Blue Marble Earth montage shown above -- created from photographs taken by the Visible/Infrared Imager Radiometer Suite (VIIRS) instrument on board the new Suomi NPP satellite -- shows many stunning details of our home planet. The Suomi NPP satellite was launched last October and renamed last week after Verner Suomi, commonly deemed the father of satellite meteorology. The composite was created from the data collected during four orbits of the robotic satellite taken earlier this month and digitally projected onto the globe. Many features of North America and the Western Hemisphere are particularly visible on a high resolution version of the image. http://photojournal.jpl.nasa.gov/catalog/PIA18033
By proving that it's a montage you are just proving that NASA is telling the truth about the photo.
If you try to disprove photos, try this one.
https://images.nasa.gov/details-PIA00123.htmlThis color image of the Earth was obtained by NASA’s Galileo spacecraft early Dec. 12, 1990, when the spacecraft was about 1.6 million miles from the Earth. http://photojournal.jpl.nasa.gov/catalog/PIA00123
As stated by NASA that photo is a single picture. By the way it's not CGI, that I can assure you. CGI technology wasn't advanced enough in 1990 to create a picture like that. For some reason I expect you to say: "It wasn't created in the nineties. That's just a lie to confuse you."
Knowing that you don't like NASA, here are some galleries by ROSCOSMOS (the Russian space agency).
http://en.roscosmos.ru/309/4) Cost and effort of lying.
NASA would have to fake all their more than 140,000 pictures (those include pictures of other planets, stars, nebulae etc...) taken from space. They also have to build rockets and other spacecraft some of which you can find in various museums. They actually have to work, because you can watch the launches. They would also have to fake anything related to space or Earth explorations of the last 2,000 years. Anyone who has anything to do with those things, would need to be kept quiet. Every telecommunication company using satellites, anyone traveling the world with planes or boats, anyone who has ever been to Antarctica, every other space agency, etc...
Here you can find an overview of NASA's budget and what they are using it for.
https://www.nasa.gov/sites/default/files/atoms/files/nasa_fy_2019_budget_overview.pdfRead it first, before complaining about it. NASA is very open with their research, many things are publicly available.
If that's not enough they also have a more detailed version.
https://www.nasa.gov/sites/default/files/atoms/files/fy19_nasa_budget_estimates.pdf5) Benefits of lying.
There is no benefit to fake it. The costs would just outmatch any kind of benefit they could make. If NASA is doing some kind of secret project, it would be a lot easier and cheaper to simply deny it and use their resources for that secret project instead of faking space travel. Additionally there would be no need to lie about the shape of Earth or fake space travel, to get some resources.
Flat Earth society:
1) The number and details of sources supporting a flat Earth.
There aren't many sources. Most evidence is only done by a few people and are very vague. Even wikipedia is more detailed than those sources. Some things don't even have evidence at all. For example the ice wall, the dome or that shadow object you use for the lunar eclipse. No flat Earther has ever gone to Antarctica or the edge of your world and written a report about it. I asked that question before. The reply I got, was someone asking me if I have gone there. I haven't gone there myself, but there are people who have gone there and wrote a report about it, took photos etc... The flat Earther talking about Antarctica or your ice wall don't even claim to ever have gone there.
Look through your own sources and think, if you would accept such a source as evidence for a spherical Earth. I looked through your library, and all of those books can be made up by a high school student.
2) Explanations for phenomena.
Flat Earth lacks quite a lot of explanations. The explanations you have are often contradicting observations. For example the lunar eclipse.
https://wiki.tfes.org/The_Lunar_EclipseIn your explanation you need a shadow object, which has never been observed. The explanation that the shadow object can't be seen, because it orbits close to the sun, contradicts the observations of Venus and Mercury.
The lunar phases are also a contradiction. In your model it's possible to see the moon from different sides depending on your location, resulting in different phases. Yet observations show that the moon phases are the same independent of your location.
3) You don't have any photos from space at all, but since don't believe in photos anyway, it doesn't really matter.
4) Cost and effort to fake evidence.
You barely have any costs at all. The only things you do is observing and coming up with explanations. You don't even bother to update your explanations, since you simply say that every contradiction is a lie. Additionally you often don't even explain, why the contradiction is wrong. Instead you just ask questions about the spherical Earth, which by the way most of the time can and have been answered even though you simply ignore the answer. As mentioned before, some things (ice wall, dome) are claimed without any kind of observation.
5) Benefits of claiming the Earth to be flat.
By convincing people to believe that the Earth is flat, you can gain new members. Those members pay a membership fee, generating money for the flat Earth society. If there are more ways to make money, feel free to add them. Since your costs are rather low, you don't need much to make a profit.
By saying that everything given for a spherical Earth is fake, you are just proving point 4 of my reasons against a flat Earth.
Conclusion:
The flat Earth society has it a lot easier to lie, and lying provides you with more benefits than it does for NASA.
It's not evidence about the shape of the Earth, it's just shows that flat earth society is more likely to lie. Ask yourselves why do you believe the people claiming that a spherical Earth is fake?