Not as much as you might hope...
Later post-Trek Pulse's are sadly not all that desirable, but are actually very good frames, 90% of the performance of an attitude but at 10% of the price, and the added bonus of being able to use any fork or BB you like. Downsides being external routing for cables, less fancy paint and less aesthetically pleasing weld finishing and a slightly lower spec tubeset, not that you'd likely notice unless you're very picky and rode them back to back...
I've seen full bikes in equal or better condition sell on eBay and other forums for between £50 (yes really!) and £250, I think you'd struggle to get any more than £200 or so.
FWIW, I've got one I was pondering selling, in better shape and with a custom paintjob, but decided not to as I thought the £200 odd quid I might get for it was hardly worth the bother as I love riding it!
Good luck if you do decide to crack on with the sale, I'm sure it'll make someone happy :-D