About 15 years ago I had a Canon 7 and loved the body, but I didn't use it a whole lot since obviously M mount lenses don't fit on it, so I sold it. I always regretted it since I found the camera to be so nice to use. Fast forward to a year or so ago and I decided to remedy the situation so I bought another one. Super clean and it happened to have a 50mm 1.4 attached to it that was also ridiculously clean. It worked out though since Canon 7s have gone down in price in those 15 years. I got a better one with a lens for only a few bucks more than the original one. Not bad.
I regret not buying an A La Carte Leica back when they were released. I thought at the time that they were stupidly expensive. Well, now new Leicas aren't stupidly expensive, they are obscenely expensive. Oh well. Maybe one of these days Leica will realize what a photographic genius I am and give me one. No? Oh well. Lol. Leica lenses are the same now too. Just way too expensive. I remember when Noctilux were around $1000, and that wasn't too long ago. I paid $200 for a beat up 35mm Summicron, beat it up some more, then sold it for $400 a few years back. Leica lens prices are nuts now. I just hope Leica doesn't decide to raise the price of the MP and the MA to like 8 grand. Then the price of every body will be obscene. Happened to the M6 and the M7. IIRC 20 or so years ago M6s were only around $1200 brand new.
I also regret not buying a Zeiss Ikon when they were new. They are way overpriced now. Though I am glad I bought a Hexar RF instead. Great underrated camera with those Titanium covers. Really is durable and reliable. I should probably buy another one since they are still relatively cheap, although the price is going up on them. I probably should not keep saying they are good cameras on the internet. Lol.