Hi Jake. It's difficult to say much without a picture of your instrument, but I'm assuming were talking about something like this. I realize this is a bass but is your guitar this style of instrument?
 
If so, it is very unusual for one of these violins to have four pickups, the standard configuration is two. Assuming the neck is not twisted or warped and the electronics are in good shape I'd say $399 is a fairly reasonable asking retail price for one of these instruments. It's probably at the top end of the price range but given four pickups, I think your pawn shop is being realistic in their price expectations. My hunch is you could haggle the price down by 10 percent or so if you are a serious buyer.