See my www.cheap-moscow.com
There I recommend you see My guide to Moscow. It is based, on the one hand, on my own experience living and, on the other, on questions, concerns, or requests I hear from travellers.
Please note the Where to stay in Moscow section. There it is realistic to find a room for $25/night or an apartment for $80/night. I know most hosts and landlords on this list and exactly what they offer.
But trying to cover Moscow in any detail is way beyond me. The best I can do is offer you my list of hand-picked internet resources on Moscow and Russia in general.