Steel wheels, yes, alloy, no. I say a U Tube vid on how its done. find a round hole, like a man hole without the cover and re-bend to straight. Well I un-spoked a steel wheel, the bugger was about 2 inches towards taco. I took several 1x4 boards, placed under each side of the rim (parallel) and bent the taco back out. Took several tries, don't go overboard and do one massive bend, go lightly and little by little. Eventually it got back to true, I did the un-sientific measurement by placing the rim on the driveway, turning 90* just to make sure the concrete is flat and so was the rim. On a 26, 26 1 3/8 and a 27 1 1/4 steel rims, each came back to at least 1/8 inch true. Re-laced and I'm happy. Now on a old vintage rim, who knows how rusted or thin, it might work and it might not.
On alloy, once bent they are bowed, cracked and just warped if the taco is real bad. Its like the alloy has a memory in the metal and it just wont go back to true.
If I had light right now I'd go take some pic's, but its dark and cold right now.
Cheap Spokes? E-bay, other wheels, your friends wheels, haha. The LBS are $1.50 each, ouch, E Bay, low as .50c each, the local bike Co op here is .10c each