My mom and dad are big on collectibles.
We went to a swap meet at the Portland County fairgrounds in Indiana for the antique tractor show, and my dad got a toolbox for his Farmall M (that mounts on the headlight crossbar) for $2. It needs paint, no dings or anything. From what he says, they are rare and worth alot more.
My mom purchased (from the same guy's wife) a fancy antique glass fruit bowl for $7 because she thought it was pretty. It was appraised this year at $1,100.
My personal bests (I am more into the 4x4 scene, so bear with me) are decent.
I got a Dodge Dana 60 front axle with 4.10 gears for $150.
I got an Eaton rear axle with 4.57 gears and a No-Spin from a '65 C20 for $100.
A 14 bolt axle with 4.09 gears and a Detroit locker for $200.
a 10 spline NP205 for $20.
a 465/205 combo for free (guy wanted it outta his garage!)
a divorced NP202 transfer case with 1410 yokes and a Braden PTO for free.
at a yard sale last fall, I scored a really nice set of 1969 Ohio Truck plates for $4, they need some paint and even have the reg. stickers. Pretty neat.