bargains are expensive

I bought a mountain bike (non-suspension) at a yard sale so I can ride on dirt roads with my kids. The bike only cost $20, but it is going to cost me $150 to put it into good working order(having the bike shop do the finicky work and buying tires and seat cheap by mail order and doing that work myself). This is why last year I initially wanted to take up running rather than going back to bicycling--too many tempting gadgets in bicycling.