Go to HobbyLink Japan (www.hlj.com) and check their prices, they charge Japanese retail for everything so at least you'll know the going store prices (not the inflated US prices).
For the Combat DigiQ, go to their site (http://www.konami.co.jp/th/micro_ir/...eup/index.html) it'll tell you the retail (in yen) as well. You should be able to find some deals in Japanese shops for bundle discounts...But I've got no clue how they do things in the land of the rising sun so good luck.