Re:
I have an 08 Hummer
I do like it very much. I use it mainly for winter riding, nearly all xc-ish. As someone who loves steel hardtails, I really like the ride feel in a sublime Ti / steel kinda way and its a frame that enjoys input from the rider, in terms of pedalling and cornering - it responds quickly and dare I say, eagerly! There's a sense of compliance, not flex.
I was running TALAS 90 - 130 and converted these to FLOAT 130 at the end of last winter as whilst I liked the travel adjust, the lack of small bump response and finding the bike nicely poised anyway even on the up's at max travel, it made sense to me. Personally, I'd love to put a Lefty on it, but other bikes and life are preventing that at the mo! At 90mm travel, the front end had a tendency to tuck under, which is not surprising as it steepens the HA quite a bit. Having ridden it this winter with fixed travel, I'm happy with it for the riding I do now. Maybe 10years or so ago, I would have run it at 110mm or so.
There are tales of these Lynksey made Hummer's being prone to cracking around the seat tube area, I have no direct experience of this, so it would be worth you checking any frame carefully and making sure there has been/is more than 100mm of seat post within the frame when riding.
As for how much to pay… Depends upon what you define as half decent and how used and abused the drivetrain, brakes, forks etc are. So anywhere between £600 for one with low spec or very used higher spec components, to £1000 if it has lots of newish X0, XT/R etc dripping off it.
As always, its worth as much as you're prepared to pay for it. I bought mine 3 years ago from a Retrobike member. It was/is kitted out with new X0 shifters, rear mech, X9 FD, new Sram asp cassette, Hope mono mini's, Thomson post, stem, EC Monkeylites, Hope BB and H/set, Hope 2 hubs and X719 rims and some Manitou Nixon IT forks, that like the rest of the used bits, were immaculate. I paid the guy £1,100. Too much? bargain? Thats for me to say really and as such, its been money well spent and I'm always slightly reluctant not to ride it whenever I can.
Have a gratuitous pic!