^Well, it depends on how you put your auctions across. I've managed to sell a lot of 7FAM at very respectable prices because I know so much about the brand, fit, how the cuts correspond with the 12 figure types, how to do minor repairs on jeans that need them, etc. I'm about to send off some WDS red A-Pocket crops that sold for about $55 plus ship--in October! (granted, the red ones are very rare, but I also haven't had any trouble selling the pink A crops when they're in season)
One trick you might use is to find stock pictures of the exact item (in addition to your own pics--never in place of them!) and use that as the main photo, with Photobucket thumbnails of your actual pics first thing in the description (mine link to the full-size pic, so I never pay Ebay for extra photos). It just makes the listings look so much more professional, and especially when you're dealing with newbies to the brand and you have older styles (like those bronze crystal sigs), they will automatically think the style is a lot more current than it is.
You might also consider lowering your prices by one cent across the board--$99.99 really does look like a lot less than $100, although it seems silly!