I have bought 1.5s for 700 stock and but with all 2.0 ups I would say 825-875ish. If you take your time and watch the threads you can get some good deals on a 2.0 for 900-950.
Ya know 915 is a bit more than I would of paid but hey it's not really that bad, mint I would say you could find one for closer to around 850 or less if its less than mint