I have a boxed (labled as Original Collector's Edition) set of rules for D&D. 3 booklets of rules and 1 booklet with tables. They are in excellent condition, no wear on the box.
I believe the "Original Collector's Edition" was released as part of D&D's ten year anniversary. I remember picking one up just for old time's sake. It's got "Original Collector's Edition" inside a sort of starburst, right? However, those first three books are quite rare, even in the collector's edition.
I'd suggest checking some of the used game sellers that advertise here on the 'Geek. If they have a copy, you can at least see how much a store thinks it's worth. I think you could get some decent bucks for the set, though I really can't give you a ballpark figure.