second hand lenses in Osaka Japan

Hi,

I'll be travelling to Osaka in a few days (first time I'll be there) and was hoping to walk some second-hand camera stores to browse some lenses... I've already read in the Nikon lense thread about suggestions of places to go ( http://forums.dpreview.com/forums/readflat.asp?forum=1030&message=35111591&changemode=1 ) but does anyone have some first hand experience purchasing from these (or similar) stores? I don't quite know japanese (so it might be hard to communicate) but I'm fine with geography so I'm pretty sure I could get to any store with an address.. that said I don't really want to go out of my way from the main travel routes of Shinsaibashi/Umeda/Namba sort of area..

Also approx how much cheaper would second hand lenses be in Japan? I'm possibly looking for the 24mm f/1.4L II or 35mm f/1.4L if it's reasonably priced second hand (otherwise I might end up with a Sigma 30mm f/1.4)

Thanks in advance!