That's either an Echo or a Rockman from the looks of it, not actually a custom frame
The local echo/zoo is dual maggie and nearly costs more than retail, I'd certainly choose new over it
but there are indeed better options used
If you haven't ridden a modern trials bike a Koxx-esque bike could just be painful and easily damaged
What riding background do you come from and what sort of riding do you want to do
So looks like you've already got a street bike, what do/don't you like about it
And why are you opposed to a mod? If you're under the impression they're for shorter people that's simply wrong