We went with a $300 replacement plan to have them replaced by a good technician. They are ~$100 when not purchased on eBay. $100 for labor, $100 for shipping (there and back) = $300.
If you can afford to make a mess of your machine, give it a try and let us know! Looks like all 5 of our TiPBs are going to need to have their hinges replaced at some point.
There was a posting that the most critical factor if your hinges are a problem is to adjust the angle. If you just replace them at the same angle, you are going to have the problem again in the future (which is what happened, Apple repaired this machine's hinges once, then we just repaired it).
I'm not sure HOW to adjust the angle, tho!