I usually only import if the game is not coming out in the US. I know you said other than Ebay but that really is the cheapest way to get the import games. I usually am able to get games for 1/3 to 1/2 the price the import stores want, less if the game is not in demand. I have even gotten a PS2 import for $1.00 plus shipping brand new off of Ebay when the import stores wanted $30.
Otherwise I would buy from Play-Asia or NCSX since both seem to have good prices but at $60+ for some games, it becomes really selective.