I need a new yoga ball

Man. Starting during my second pregnancy, I started sitting on a yoga ball while working. Not too long ago, the damn thing popped. (I know. They're supposed to be able to withstand... I mean, I was pregnant! ugh.) Anyway I've been sitting on a crappy kitchen chair since then and ow. When I stand up after working for a few hours, I walk like Marlon Brando when he was chasing that kid around with an orange peel in his mouth right before keeling over from a coronary. In The Godfather, obvie. You knew that. Anyway, this is apropos of nothing except that I'm sitting here working and my butt hurts. Do with that what you will.