OcUK has stock of no less than 10+ Radeon HD 3870 cards from HIS. The cards are stuck at reference clock speeds. so don't expect anything out of the ordinary. We're not sure if they will use AMD's stock cooler or HIS's own cooler.
You're looking at £164.49 inc VAT for one of these cards, and it's about the going price at the moment. You can pick one up here.
OcUK is already discounting HIS Radeon HD 3850 cards, and again, the compay appears to have plenty of stock. It's not super low priced, but we're getting closer to the £100 price point, inc VAT, as the cards are listed for £105.74 inc VAT. You can get order one here.
Finally, OcUK also has stock of some Sapphire Radeon HD 3850 cards for £108.99, which you can find here.