I bought a Cheapnese one and regretted it; the threads were so poor that one stripped within half a dozen blows. Chopped the end off and retapped it, made a new end fitting and tried to use it to whack out a stuck diesel injector - stripped the other bloody end. Utter cack.
I would think for most dent pulling you don't even need much weight in the, er, weight
Making one is indeed dead easy, but if doing so make sure your weight is ergonomic and try to make it difficult to trap skin anywhere.
Very cheap tools... I considered buying a cheap one for blind bearing extraction a while ago but didn't. It seems just about everything, no matter how basic and simple, can be made from monkey metal ^^^.