as far as wheelbuilding is concerned, if you can thread a needle and follow a cooking recipe, you can build a wheel.

but the tool investment is intense: a $4 spoke wrench and a screwdriver. you already have a truing stand, your bike.

if you go used, just make sure all the spokes feel good, tight and without rust, spin the wheel for feel and check the rim for defects. buy brands in which you're familiar. and buy the right rear wheel for your bike (126mm old with freewheel hub). you probably won't know what the hub races look like until you get it home.

there is some risk in buying used. i bought a great used set recently: shimano 600 hubset on italian rims. it was a good deal at $75. i bought it knowing the spokes needed to be tightened -- no big deal. when i went to tighten the spokes, they poked through the rim tape. no wonder the seller was getting rid of the set. i guess he didn't want to re-lace the wheel. it turned out to be my first built wheelset -- bought new spokes and trued both wheels inside my bike's frame. it's a great feeling doing it yourself.