I just finished putting together one.

Found a Mongoose frame with no wheels, horizontal dropouts in a snowbank on garbage day.

I needed Wheels (complete)
Real crank
frewheel

Ordered chear 26" wheelset $40
Tiers 'n tubes Wally World (YUK) $30
Ebayed a crank with 39 ring $18
Chainring bolts and 16 freewheel $15

Suppose I should get a chain that ain't all messed up

Time to go play in the snow! and get off the trainer.