depending on your previous travel experiences, rwanda is really expensive. i'm surprised that travel in east africa costs what it does (having lived in asia for several years), but rwanda is nearly double the rest of east africa.
in kigali, i've stayed in dump hostels for $10 a night, and a nicer guesthouse (with shared bath) will be around $30-40. a "mid-range" hotel, if i know what that is, is going to cost you at least $60-70 in kigali, and a little cheaper in ruhengeri (which i think is now named musanze or something like that).
i don't know bus prices as my last several visits to rwanda were in a private vehicle. mutzig beers are great, and you can find them on tap at some of the nicer restaurants in kigali ($3).
jamesbrett