Sure! I can tell you the best places to go...
#1- Go to Tokyo
#2- Go to Akihabara
#3- Go to the "Akihabara Electric Town"
#4- Walk down the main strip and find used anime stores, like Trader, etc, (I forget the exact names)
Look for used copies. They are usually 50% the cost of the original. The originals are bound to be there too but they are bound to be expensive. If you need more help I will be glad to oblige!
-Tofu