helping a dude out
 

I am rebuilding an old AMF pro tour bicycle that I picked up at the salvation army, for this bum buddy of mine that spends far to much time walking. I figure as long as I am rebuilding might as well convert it to a singlespeed. He is a good friend, but I don't want to put too much money into this bike. Can I put a used bottom bracket, cranks, chainwheel, and wheels on for less than $75??

you won't find anything that's not beat up and old.
your best bet is probably to look for an old crappy looking bike for $75 that hopefully has decent components and strip them off of it.

Yup. Or you can search out places that "recycle" bikes. There are a few of them in Chicago that are pretty nice, where you can get a ton of components for cheap. I dunno about that being the case in Wyoming though....

update--

bought a new bmx bottombracket $7.95, changed out the tires from another old bike (that were better), going to spacer out the cassette instead of singlespeed hub, just need a chainring, and brakepads