I have had my braces off since November of 2006. I have had a retainer ever since. Today (June 4, 2007) I went for a retainer check at the orthodontist. My lower right lateral (number 26 tooth, the front, bottom 2 over) has moved a little bit inward. It is noticeably out of line from the others. I truly wear my retainer every second I am not eating or brushing my teeth. I asked my orthodontist how much it would cost for another one. He said $250. I asked would it work, and he said, "Only if you wear it" (which I would not have a problem with).
My question is... Should I have to be the one to pay for the new retainer? Since I have been wearing it all the time, is it my fault that the tooth is moving if I have the retainer in my mouth all the time?

I want straight teeth, but I do not want to have to pay $250 on top of what it cost me for the rest of the process.

This is a toughie because it really depends on what your contract with your ortho said. It is possible your ortho took your braces off too early and the root on that tooth hadn't settled, but it's also really common for teeth to move after braces have been taken off, even with retainer wear. What sort of retainer do you have, the plastic tray kind or the metal wire? If it's the metal wire, it's possible the retainer wasn't fitted properly and your ortho should have picked up on that during previous retainer checks. Also, he MIGHT be able to put a bend in the wire to correct the problem, instead of making a whole new retainer. As for the plastic tray style retainer, I've heard "bumps" can be placed in those to nudge teeth along, but your ortho may not do this.

In the end, it all depends on what your contract says. You might ask if there are ways to manipulate your retainer instead of getting a new one, but it sounds like he is hell bent on charging you for a new one.

This frustrates me. There is no reason that you should have to pay for another retainer, if you have truly been wearing it like you're supposed to. If the retainer were properly made, you're teeth shouldn't be crooked. Your ortho needs to pay for the replacement. Not you.