Unistream seems to be the most popular system. Works exactly the same as WesternUnion. 1.5%, 1% if the amount is over 30 th. roubles (just under $1000US). Most cities with pouplation over 50 thousand will have a Unistream (Унистрим) office.
The closet one to my apartment that’s available for rent is in the Fish Market (Рыбный рынок).