(re: Looking for sierra games) Amazon has nothing to do with price… it’s driven by market forces and if a seller beleives the hype and will actually make any sales at those prices then ‘good luck’ to ’em. There’s also a games trading zone which has equally stupid prices.
eBay is bar far and away the best marketplace for this type of thing. However, you’ll be hunting for a while to find a) what you want – exactly down to boxed, with manuals, etc. b) for the price you’re willing to pay c) choosing the person most likely to complete the sale as stated, etc… It’s far from perfect with far too much end auction sniping for my liking but you can get ‘lucky’.
From the two you listed. Leisure Suit Larry comes in one of 3 collection boxes. Collection 1 which is labelled in Europe as the Collector’s Edition and elsewhere as Greatest Hits & Misses. Collection 2 (bigger box with flap labelled as Collection Series) adds a talkie version of LSL6 and comes with a great book on the series. Collection 3 is the Ultimate Pleasure Pack and includes LSL7 but with no book… The 3rd pack is the most difficult to get hold of and it’s eBay price is usually $120+
King’s Quest is available in one of 5 box sets. 3 are near identical bar some packaging detail. This is the 15th Anniversary set which comes in a box with cool looking embossed text, in a standard slip case box with fairly bland pattern or in a (possibly US only) release with some unusual drawing on it. (Peter’s site may have the box shots!). Like LSL, the KQ collection was also treated to the Collection Series large box set and finally all of the KQ games are included in the Roberta Williams Anthology boxset. All very cool if ya can get one/all of ’em 😉