A classic lever with "QS" on it is 2007/8 vintage (although as an aside, I have been told that Campy is still making this style).
As I said before, up till '07 the internals between Centaur & Record are similar. In '07 Campy made a switch in the Centaur internals at the same time going to "QS". Those Centaurs have an "escape" mech, the cheaper "one shift at a time" system. The action of the left lever became like a trigger - and in doing so the fine trim was lost. Not knowing this I bought a set, and was most disappointed.
I don't have personal experience with the Record/Chorus "QS" versions, but I believe they did not suffer this problem. They are in stock at several retailers, whereas for the older ones ebay is the best source. these may include cables - you have to ask.
As for price - here are Records for $290 http://www.cyclesuperstore.ie/shop/pc/viewPrd.asp?idcategory=80&idproduct=2968
alternative Chorus & Record here http://www.chainreactioncycles.com/Models.aspx?ModelID=26038
I have dealt with these guys - cables included. If price includes UK VAT (I'm sure it does) then take 20% off - so $240 http://cgi.ebay.ca/2006-Campagnolo-Record-10-Speed-Carbon-Ergopower-Levers-/160547568150?pt=UK_sportsleisure_cycling_bikeparts_SR&hash=item2561617a16