I've only bought one lot of open, unbuilt kits. I got a good deal because the seller didn't mention what they were, noone searching for them would find them. One kit was half off the trees, but all wre complete. I got a newer 1/24 Monogram 39 ford 5 window, Revell Tuners Datsun 510, AMT reissue Berrien T buggy, and a Monogram Nascar McDougals T-bird that I traded for a Revell Ritchie Ginther Porsche 914-6, missing the window. Lucky? Maybe.
On another note, anyone dumb enough to ship a model car in a padded envelope needs to be taken out back and beaten.