If this had been said as advice by anyone else, or anywhere else, i would be currently ripping them apart. But since it isn't i'll refrain.
I bought a Mirra co for £250 that was £600 new from them a few years back, when chainrings didn't get smaller that 36t.
I would deffinatley look second hand, its suprising how good some of the bikes you can get are, they tend to be abused less than trials bikes (Visually that is.)
I bought a 2005 Fly diablo with basically a full oddessey frame kit for £50 because the rear hub ha broken its spring...
Also bear in mind, if your tall that doesn't mean you need a mahusively long frame, I've had 20.5" all the way up to some ridiculous lengths, i think my federal 1066 was 21.75" I may be wrong.
Cromo as everyone else said is always the better option.