Yes, games can get expensive if they are exported out of HK. But some stores buy in such large quantitys, they never go over 20$ per disk. Most of the time the disks cost alot less. But it depends if you want originals or Just want the game.
Also, unless you got your system from a chinese store, most of the time you need to get a Mod board from HK to make it work with games. But you can always open up to see.