The rollers (anvils) are expensive if you buy the real mcCoy stuff. But plenty of guys have built fairly good wheels using castors, large bearings etc. If you have a friendly scrappy nearby, and are allowed to trawl through their stuff you will be amazed at what you can find. I try to make a habit of stopping for a quick look every time I pass my local one.......
Also you can do a surprising amount of shaping without a wheel - or any other machines for that matter. Learning the basics of what the metal is doing is actually probably best with hand tools - you tend not to make scrap metal quite so quiclkly



Let me know if I can help ever.
Barry