IF you want to do paid shows, you'll need to go for the Eval kit (licensing), and if you want to invert a set of scanners you'll probably want to request the differential board as well.
Eval is about $550 and LivePro USB is $250 (or was when i bought it over Christmas - note this was the regular price as it wasn't included in the holiday specials)
By my reckoning you can still pick that up new (even with the crappy exchange rate) for £550 (plus import duty/VAT) Might be best to buy the eval kit only so you only pay import on the $550 rather than the LivePro software too. You can get the software electronically direct from Pangolin separately (which is what i did) so no customs charges.fb3 evaluation pack with live pro for £650 which is an absolute bargain