How much would invasalign cost to straighten one tooth

I had braces and had straight teeth and wore my retainers for 2 years. Well not great but after the initial 6 months I'd put them in every so often my bottom ones were always fine but my top ones, a particular tooth always moved. Now about a month ago my dog chewed up my top retainer, and my tooth the one tooth was already going a bit wonky so I then didn't see the point in getting a replacement. Now it just bugs me sm I feel like it's moving more.

I'd be interested in invaslign but I don't really have money now for it. I don't want to straighten my bottom teeth I just want to straighten this one tooth on my top?

How much roughly do poeple thing this would be, it's mildly wonky I just hate it poeple say its not noticeable. But any ideas???