Thank you for your detailed response, mgb74.
KEH is not currently buying the FTn; they likely have more than enough for the demand they have. Likely it's due to it using an obsolete battery with modern replacements being too expensive to be economical. The camera works perfectly without a battery though, obviously.
I know that KEH will pay me more than I paid for the camera and lens for just the lens alone, which is why I initially purchased the camera at the thrift store. I know enough about old Nikons to know that I wasn't sitting on a secret rare camera, I just didn't know what it was worth.
I have not done a full comparative test of the FTn, since as E. said the battery in it is not to be trusted. The shutter speeds seem to be accurate and the camera seems to work in my limited playing. I honestly don't want to put the money into it to buy a Wein cell. It will more than likely go on eBay as an as-is camera. The lens...still deciding on what to do with it. I may send it to KEH for a quick turnaround, but I may also post it on eBay. I'm sure the EOS video junkies will buy it and not worry about the AI conversion; they'll slap it on an adapter for their 5D Mark II.