Apples and oranges there. The companies that keep churning out "newer and better" models put the higher price tags on their most recent over hyped technology which some folks are willing to pay for. ProKennex has a bit of a corner on the market with their patents and there's a pretty consistent demand for their Kinetic/Ionic frames; they don't have to reinvent them every year for people to keep buying them. Since their Redondos are solid true player's frames, there will be more of a slow-and-steady demand for those, too, but not among the weekend warrior/club crowd that likes to have fresh gear every year or two.
Honestly, I really don't know how long Prince, Head, and Wilson can go on reinventing the wheel almost every year, but they're making a living at it, right? Different companies obviously have different approaches with marketing - if you get a chance to talk with someone who works in the industry, they can probably give you a bit of an education on the whole grind that it takes to get a piece of the action. Aside from the brand new frames, I'm pretty sure that the sellers are still making some money on the clearance gear, but it just doesn't have the buzz around it that boosts the profit margin.