Go poke around at hobby-machininst.com, you'll find that the vast majority of people there are retirees who got bored in retirement and picked up machining as a hobby. Some of them are making money at it, but mostly it's just for fun. And it IS fun. I have two lathes (one little 9"x36" that works and a big girl 18"x80" unstarted restoration project) and a CNC mill that is nearly fully restored. Working with these tools is very gratifying. IMO even more gratifying than welding, bending. If you're telling yourself you're too old to get started, well you know yourself better than I know you, but it smells like a cop-out from here.
Don't worry about losing interest in it and chasing other dreams either. I'm the same way. Being able to run a lathe & mill, once you can do it, is like being able to drive a car. It just keeps coming up, no matter what you get yourself into. You want to get into electronics? Well you can mill PCBs; no need for the nasty etching process or paying the Chinese. I could list more examples but I don't see the need. It's a useful skill, period.
I have a Hougen magnetic rotabroach in excellent condition with extensive set of metric & imperial annular cutters. I got it for an amazing deal and don't use it very often. I fell on hard times a while back and tried to sell it, no dice. I got zero interest in it posted on online marketplaces. I only got a single phone call, and only after I had lowered the price to $250 (half what I paid for it) and they were trying to talk me down even further. I took it to at least 6 different pawn shops and they consistently refused to make me ANY offer. They just didn't want it, period. They didn't think they could sell it. I was baffled. Still am. My best guess is that the people who are in the market for these things are large businesses who don't check craigslist before buying; they cut a PO to the nearest distributor and get one delivered; there just isn't enough joe blows out there looking to buy them used. I say all that to say this: if you can find someone trying to sell one, don't be shy to offer 25% of the asking price. It will probably be the best offer they get, and they may just accept the offer. (And no, I'm no longer looking to sell mine; I'm glad to have gotten thru that rocky patch keeping my magdrill)