I bought a used Diamondback Maravista off craigslist for $100 last spring. Probably put a couple hundred miles on it. Rode fine. Then in the fall it started "slipping" like a half of a pedal rotation here and there, especially when first starting to pedal after coasting. I didn't really use it since then because it was winter, but we started having some nicer weather recently so I took it into the local shop. He said it probably just needed a gear adjustment which was $25, but a tune-up was $40 and would include the gear adjustment so I got that figuring I probably should have had a tune-up when I bought it because it looked like it had been sitting for a while. I picked it up yesterday morning and rode to work. At first it felt good then started feeling it slip a couple times although very minor, but still enough to know it wasn't fixed. Then on the way home it started slipping like crazy. I was pedaling and nothing was happening. Then I realized all the gears were spinning just not the wheel itself, which through Google led me to the rear hub and the pawls. How much is this to repair if they're broken or if they are just sticking? Is this something I can fix myself? The diagrams I saw of rear hubs make it look a little complicated. It's just the bike was only $100 so I don't want to spend a ton of money repairing it.