I have a Fatboy. I rarely use it. It was given to me by a member here and cleaned up very nice. I don't think I'll ever part with it. Should I sell it here on the sites, and if current prices are to believe, it should get me around 130 USD. It's crazy. It's not even mint. But I do have the case.
I bought two at a yard sale just over a year ago. I kept one and traded the other. I like it but rarely use it. I'm happy to say I have one but I will likely never buy another.
I think that part of the enjoyment of going after the fatboys is the kill... sort of like hunting. Unfortunately as you mentioned, it's too bad everyone is hunting the fatboys!
I own and have used three versions(FB, Slim & Super Adjustable) of Gillette Adjustables. I got VERY nice shaves from all three. I used them when I first started "traditional" shaving, during the time I was using Adjustables I came to favor the short handled SA the most. Since then however, I've found I enjoy using 3 piece razors much more. When comparing the prices on eaby for vintage razors, specifically FB's to modern Merkur adjustable's (Progress/Future $60-$70) most of the FB prices aren't that bad IMO and some FB prices are downright cheap! After all the FB shaves every bit as well IMO as a modern Merkur, is built at least as well if not better and comparatively speaking is rare(only made for 4 years). So IMO the Gillette Fatboy adjustable is a viable, useable modern safety razor that also has considerable collector value and can still be obtained for a reasonable price. It's a Fantastic American made adjustable safety razor, that's is not only well made, but is a piece of American history.
I'll wait until the new year. I have my November rule and in dec I'm going to try to focus on straights with a rolls backup. That gives me time to sort out my legal issues with my ex wife as well.
I got my FB from a member for $40 last year. Then spent $70 getting it played in rhodium. (But, today only you can have it for $500. LOL) But, it does seem that razors, in general, are getting more expensive online.
I was fortunate enough to buy one years ago, and I picked up another in a trade. So now I have one for daily use, and one as a spare. Alternatively, I may send out the more worn one to be refurbished.
You can have this one for $250. It's a 9.5 out of 10. Original. 23K gold plate with clear lacquer still perfect.
My first DE was a fatboy so I judge all others by it's shave. Should I ever settle down and try a 30 day focus I'd choose another. The FB is my go to for days when I don't feel like a straight. I'm still not skilled enough to get a DFS with just the straight so 195 is my touch-up tool. I'm in possession of three FatBoys now for a total investment of $25. Can't see selling them, but I might put em in my will for my three sons.