You can do throttle bodies ALOT cheaper yourself & providing you take your time & dont cut corners that are going to spoil it then I say go for it.
What my throttle bodies will of cost me when I've finished....
Jenvey Twin 45s, inc injectors, fuel rail, throttle linkage & regulator, Trumpets (ebay), Airbox (yet to purchase), Adaptronic ECU & loom, Manifold, Gaskets, Loom, Throttle Pedal & Cable - £1260.
Obviously then theres my own time for fitting everything including the loom & mapping which I'm going to take a shot at myself.