I understand your frustration but you are wanting a PCB that has been selling on eBay for like you said over $500. Lunar Landers are expensive and pretty hard to find, so the prices are up there. Again i feel for you i know these things aren't cheap but that is what they have been selling for, and have been for a while now. Not saying that is a good thing or bad thing it's just the way it is, Lunar Lander was made in 1979, Atari's 1st vector game, they gotta be hard to find, it's been 31 years since they were made.
There is one right now on eBay for $300 plus $18 to ship, this is a pretty good savings vrs the $500 we have seen these sell for over the past while. So if your looking for a fair price, while still a lot of money i think $300 is the best your going to do. I wish you luck i really do and that you are able to save another LL and enjoy it for years to come.