Lots of 'cheap' deals if you go back some years,,but I'd guess you'd have to apply that inflation guestimator thing to figure out what the real cost was in todays money.
Stuff like a 1911 Colt (made in 1918) with the belt, holster, mag pouch, 3 orig mags and approx 200 rds of WW1 & WW2 ammo sounds like a killer deal at $60.00. But the pistols alone were a $50.00 item when I bought that one.
A 95% Luger BYF41 all matching w/ holster and mag tool for $100,,again about market price at the time.
I did buy a Box-o-Gun last year. A Webley MkIV WW2 'War Finish' 38-200. All in parts, everything was there he said. The owner was frustrated as it wouldn't go together and function correctly he said. Something wrong with the trigger was his final opinion. I bought that for $20 'as is' for the parts.
It went together OK.
Needed a few screw slots fixed up from the gunsmith attempts and the cylinder bolt needed some work,, but other than that, it ended up a pretty clean 75% revolver w/an excellent bore.