Hmmm... lets see. The rig that currently runs and I drive the most right now is the '84 K5.
Traded a '78 1/2 ton 4x4 truck for it. I was into the truck maybe a grand.
Traded for 3/4 ton axles (14 bolt FF and 10-bolt front) which I put under it, and I sold the 1/2 ton 10-bolts for $300.
Traded off the old rims/tires.
Paid $100 for 15x10 8-lug Chrome spokes.
Have about $200 into the 35" BFGs on it now.
Traded for the light bar.
About $350 into the winch and bumper.
Traded for the 4" lift to replace the 2" lift.
Put the 350 motor out of it into another Blazer I kept a 454 out of.
Sold the TH350 tranny out of it for $150.
Traded the 27-spline NP205 and adapter out of it for: a set of 4.56 gears for a 60 and 14 bolt and a set of low tread 37" Swampers.
Kept an SM465 and NP205 out of a '73 K5 I parted out (I made $60 profit and kept the 465/205 for free on that deal)
Clutch $100
Flywheel $100
Motor: Traded to get a SB400, tore it down to a shortblock. Used all used parts I traded to get on the motor, except I bought a new gasket set and oil pump pickup tube. cash out... $100. Got the cam, gear drive, roller rockers, RPM intake, carb, headers all off other rigs/motors or through trades. Had the work on the heads done through a trade for two old motor cores.
I think I'm into it about $1500 cash value and a bunch of trading all said and done.