I like to create characters a lot. For beginners: it makes them understand how the character fits into story and rules and is key to understand how you translate what somebody thinks his character is like and how the character behaves into game terms/rules/... . As advanced player and/or DM I like to sit down with my DM respective player to create a character and build it up, adding to the background while filling in the charactersheet. (e.g. rolling base stats will immediatly give you a mental image of the character: strong and wise but lacks inteligence and is butt-ugly...)
So, would I buy such a collection of PC's? Nope, or actualy maybe, but to me that would just be a list of NPC's. I would consider a character created by a player (or player+DM) a PC and a character from any other source (collection, net, program, publication, ...) an NPC (even if the character is played by a player). You could say that a PC then means "character created by player" and NPC "character not created by player".
The only purchase I would consider in relation to PC's ( this time meaning characters played by players) would be a program that generates a "PC" on the fly with equipment and background outline. This would be used for on the fly PC's and for cons/one-offs/demo's. (since I use a laptop at the table, I would prefer a program, also because you would be able to create a lot more variation than would be possible in any publication. just think about it: a phonebook size publication containing a dozen different pc's of all possible combinations of class/race/prc...)
