If you like the B&W house sound, why not go with some 805s?
I'm with Rlwainwright, if you love the B&W sound, the 805 is a great option. They're easy to find, plenty of supply on the secondary market, and they hold their value very well so even if you were to change things down the road you'd get back 80-90% of what you spend on them. I understand the urge to try new things, branch out and try new brands, but if you love the 803 sound then sticking with B&W and going with the 805 may be the bird in the hand...
Depending on condition - quantity and severity of chips & scratches, tweeter dimples, any other cosmetic issues - and whether you have complete packaging, manuals, jumpers, etc. I'd say a range of $2500-3200 is probably not far off. I haven't shopped for a pair in a while, but I think that's a close approximation of the current market.