Between 50 EUR and 110 EUR depends on the location and the quality of the hotel.
You can check the hotels out here: www.booking.hu
If you like apartments also check this out: www.7seasonsapartments.com. Usually I stay with them when I go to Budapest and I love it. The apartments are very comfortable, friendly staff. They are in the downtown, close to everywhere.
The food very good. There are some all-you-can-eat place, but usually you can find very good food everywhere. The price usually between 1500 HUF and 3500 HUF / person, and up.
If you go there, you must visit any Spa. The Rudas is awesome: http://www.budapestgyogyfurdoi.hu/en/rudas/history .
The most beautiful and the biggest one in Europe is the Szechenyi: http://www.budapestgyogyfurdoi.hu/en/szechenyi/history
Also if you want to know about Hungary a little bit more you need to visit this: http://www.terrorhaza.hu/en/museum/first_page.html
I hope find those information useful. almost 6 years ago