You might consider what I used to do to be more akin to Barter Kings.
I did this numerous times but, off the top of my head, here's one:
I started with a Jimi Hendrix poster and an old radio out of a truck.
traded the poster and radio for a Mongoose bicycle->
traded the Mongoose and an old 16ga H&R shotgun (free & clear from a previous trade) for 2 Marlin model 60's (+ scope, rifle sock)->
traded both of the Marlin model 60's for a Maverick 88 (+ slings, shells, case, etc) and a really nice dartboard (still in the mancave)->
traded the Maverick 88 for a FEG SMC 380 (+ holster, ammo)->
traded the FEG and a Wii (free & clear from a previous trade) for a Taurus PT740 Slim (+ holster, ammo)->
traded the Taurus PT740 Slim, 50ct box of .40 ammo & $100 cash for a Glock 23 gen 3 (night sights, 3 mags, holster, etc)
So I may have been out-of-pocket $100 cash (the items that I kept notwithstanding-dartboard, ammo, etc.),
I went from a Jimi Hendrix poster and an old radio to a Glock 23
Anything NFA bought in the 70s.
If your Ruger has a factory adjustable rear sight, it's a Mark I. If it came with fixed sights, it's a Standard. I have a Standard with a 6 inch barrel, made in 1976 and has the Bicentennial inscription on the top of the receiver.Old Ruger Standard or Mark 1... unsure what it is exactly, I think it's a Mark 1 though. Anyhow, best deal I got on it: Free. (It was a gift from a family member)