Hey! I have a 2004 Lemond Nevada City. Purchased in 2006-7. It hasn't been used as much as it should, and is in pretty good shape. Does anybody have any clue how much a bike like this might be worth? Thanks!

Those aren't worth a lot, depending on condition no more than $125 if it's mint, otherwise if in average condition $100 give or take $10.

Unless you live in an area that has ridiculously priced used bikes then you could add another $50 to the prices I mentioned but that in my opinion would be crazy high for that bike and I would never consider it.

Hard to give a usable appraisal of a bike without seeing pictures of it. However, these bikes came with brifters and many used bike buyers want those rather than downtube shifters. If it were clean, in good shape, and had recently been overhauled, I could see asking around $200.

Here is a Bikepedia link to your bike. 2004 LeMond Nevada City - BikePedia

Apparently a $629 MSRP and entry level components doesn't stop somebody from listing a 12 year old bike for ~80% of the original cost on CL. See this listing in the Boston area.
2004 lemond Nevada city 58 road bike

I love using Bikepedia to find out the MSRP for bikes newer than 1993. It's a valuable tool.

Right, but a person can list they're whatever for whatever price they want, in the example you showed a person could have listed the bike for $900 and brag about how high end the bike is. Just because a price is put on something doesn't mean that something is worth the price. In some cities like Chicago, NY, LA, etc you'll see a lot of overpriced bikes, but there are enough dumb people in a large city that don't have a clue about bikes and will buy one for a lot more than it's worth.