Ummm, as far as I've seen, Warwick's hold there value better then most mass produced basses. When you can find used fenders for under $100 you have a hard time finding used Warwick's under $500. Plus I think they look better then any other bass, but that's just my opinion and prefrence
I don't know where your looking, I got a Proline for $400 and a thumb BO for $800, thats just a fraction of what they went for new. Could you please point to a $100 fender (squier?)