Was wondering if anyone knows of a website for checking current prices of antique sheet music?

Answer 1

You can try eBay, but that is too obvious. Here are couple of other places:

http://www.eclecta.com/catalog9.0.html
http://www.tias.com/stores/finds/
http://www.sheetmusicplus.com/a/song.html?id=86135&song=Antique

With the second one, just look for the link to sheet music at the bottom. Hope this helps.