This thread might be slid over to the valuation sub-section, just a heads up for ya.

A frame is worth what the seller will sell it for and what a buyer will buy it for. LeMonds are sort of in a funny position, some like them, some don't, some think they're worth a lot, some don't, I don't know how they'll be in years to come. But with that said I'd really like to find an early to mid-90's LeMond.

Just as a price comparison here are some links to the local Milwaukee WI CL:

LeMond frame, $100, doesn't say year/model/size:
http://milwaukee.craigslist.org/bik/1121223246.html

60cm LeMond Ventoux for $795, I'm thinking he might be high on his price, but look at it quick before it goes away so you can get an idea of how that frame you're looking at might have been originally built up:
http://milwaukee.craigslist.org/bik/1159406310.html

1999 Greg Lemond Chambery for $995, again I'm thinking high for price but I'm probably wrong, looks nice though:
http://milwaukee.craigslist.org/bik/1141328728.html

And as to your sizing question, size matters when it comes to bikes so be sure it will work, the LeMonds I've sized tend to run longer in the top tubes.