a ton? Look on ebay for guide prices (altho some stuff second hand goes more than new so look at a few) Also worth noting the lifetime warranty doesn't apply to these IIRC...
thats right no lifetime on them. i dropped mine(18v) and it as never the same again. the mechanism inside dislodged so i reparied it but the power just isn there any more.
If it was the new 18v one with the slide on battery then it is well worth 100-200. They're 411inc vat with bat and charger when new and are an awesome bit of kit. Miles better than the sealey/dewalt ones. Don't know about the older ones though.
The snap-on guns are on this months offer sheet at 399 + VAT, hassled my dealer till he dropped to 280+ for a new one, 475nm of torque, not bad for a cordless
If you're not in the trade, I'd call a SnapOn cordless gun quite a luxury, unless you basically being gifted it.