As far as I'm concerned, the longer they're in print, the better. The prequels are only available separately so I think they complement those nicely. I would think the stores would like being able to stock all 6 movies in a consistant style on the shelf.
By the way, I bought Star Wars the day it came out, Empire a little later in November '06 and Jedi in March '07. I never paid more than $15.00 (half the msrp) plus tax for any of them. You just had to compare stores. Even Borders started selling them for 20 as their regular price (not on sale) around November '06 and they rarely sell anything for less than msrp.