How does the cost to install carpet in a basement change if the basement flooring is already finished with sealed concrete as opposed to if it's a bare basement? Do you have to do something about the seal, or do you just install the carpet on top of the seal? If you don't just ignore it and install over it (which is my hunch), about how much does that add to the install cost? I know the best way to get this answer is to get quotes from carpet installers, but that requires getting quotes from carpet installers and that's something I can't really do at the moment, so I'm hoping the CB experts can chime in.

Also, while you're at it it, if you happen to know, what's an approximate range of price per square foot (or square yard, if you prefer) for it?