Oh,I see,you are going to Tokyo?!I don't live in there,so I don't know much about the specific prices.But if you want a monthly accomodation,I'm afraid,you'll be charged much.Besides,how much will you have to spend depends on the hotels you choose to live in.10,000 yen per guest is at the average,20 or 30 thusand is a bit expensive but will bring you better conditions.Well,if you want somewhere economical,I suggest you choose business hotes,whose accomodating environment is probably not so perfect.