[trunker]

if you do have trouble with the see id thing and a shop wont accept it just move onto the next shop. if youre going to be shopping anywhere other than the really small local shops chances are the prices wont vary that much for whatever youre looking for. smaller shops are sometimes more expensive anyway. its very different from the way taiwan or hong kong might be where one shop might give you a great deal.

take enough cash, and bring extra just in case tokyo works out to be pricier than you thought. its really safe, unless you go looking for trouble, so take as much as you want. since it sounds like there are 2 of you going split it between the two of you just in case anything happens, however unlikely.