I think a lot of vision centers will adjust them for you for free, don't they? I've done that before, just walk in and have them do it.
The place referenced in the previous post is based in China. The glasses (frames AND lenses) start out at $8. It's just crazy. You obviously get what you pay for. My husband ordered from there about 6 months ago and he was pleased. He doesn't wear glasses every day - he mainly wears contacts and the glasses are just for at nite.
I just went to Wal-Mart today and just to get LENSES for my current frames, it's going to be a good $150. It's just ridiculous how much this stuff costs.