First place was in a church's basement. This was a really informal class, taught by a friend, though, and nobody was ever graded for rank.
Next place was at the fellowship hall of the local YWCA. My teacher was actually quite good (thanks, Sensei Sherrie!) and the rent was cheap, as were costs of the classes themselves. All I had to do was pay 25 bucks a month for tuition, and a yearly 20 dollar membership to the Y. I guess the only disadvantages were that the fellowship hall area had a dirty floor, and that the last Thursday of each month, the Y management would kick us out, so that the elderly folks could play Bingo. Once in a while, they'd let us use the main gynmasium, though.
When I went to college, we were using the fencing gym for classes. Big, wide, open area, and the semi-padded floor (floor had a bit of give, but still a relatively hard surface) had a good texture. The front of the gym had some polished steel mirrors, and we never had to worry about class schedules interfering with other groups. Dues were 50 bucks / semester, which was a phenomenally cheap price for some truly excellent training.
When I went to graduate school, I signed up with my first commercial, stand-alone school. Prices were much higher, at 50 bucks / month, but after seeing how the classes were conducted, and the quality of instruction, I was quite willing to pay the price.
Ever since then, I've been training at commercial, stand-alone schools. All of them have been well-equipped, and have high quality instruction. Furthermore, they are all places where there was always a very healthy mutual respect between my teachers and me. This combination isn't easy to find, and I'll consider myself fortunate to have found such places.
Two of these three schools had padded mats covering the floor, either the jigsaw types, or rectangular ones that stayed in place.
My current place has jigsaw mats available, but we prefer training on hardwood. I enjoy training on both types of surfaces, so it really makes no difference to me, now that my feet don't get blistered anymore!
Prices for tuition have varied from 55 bucks / month, all the way to 75 bucks / month at the recent schools, but it was certainly worth every penny spent.