Bit of a different post, non-D&D related. Thought I would list here some of the better model shops in Akihabara for anime/manga/pop-culture. Google will give you a list which are mostly hobby shops which is not what you want (for example TamTam and Animate).
Volks Inc is a second-hand store and has the largest collection of models out of those listed here. Just a note that if you see models displayed in glass cases these are second-hand models. You will get them much cheaper than the original boxed versions but you won’t get any box. Map.
All these places accept credit card as well.