A stupid noobie question, please - I see SS wheel sets on flea-bay for under $100. Are they worth the $$ or should I spend an extra $50 to $100 to get name-brand rims and sealed-bearing hubs?

I plan to keep the bike, but at the upper end of wheel set prices, I can buy an entire fixed-gear bike for the same price. Of course, I'm aware that sometimes you get what you pay for...

Where is the best value to price ratio in buying single-speed / fixed-gear wheels/bikes?