If you want something cheap to build with long travel forks, disks, risers etc to be trashed round places like the Peaks/Lakes etc I reckon you'll not go far wrong with an Inbred.
Although they're built of gas pipe the geometry seems ok and the frames are a tool for a job. They are almost cheap enough to be disposable too. Know a few with on-ones. They all reckon they're nothing special but work.
Was looking for a relatively cheap 'new school' hardtail a while back and considered an inbred. Ended up with a pipedream which is similar - almost the main deciding factor was the frame wasn't a on one
The frame is built of plumbers left overs like the inbred and the ride is pretty non descript but
I can chuck it down anything without caring.
On the flip side if you're looking at a lightweight build with a shorter or rigid fork for general xc duties I'd concur with the others and go for something 'nicer', retro and second hand.