I was at Marshall's and found these Nikes on clearance for  $40:  (Edit: won't let me post link... they are Nike women's flex supreme tr4.) I wanted to read some reviews before buying and it's so annoying that feedback is always skewed by obese people. It wasn't the shoes that hurt your knees, it was your superfluous body fat! Anyway, great buy at that price. I usually buy cross trainers. I do mostly bodyweight / gymnastics but run once or twice a week (short distance). I don't usually do well with running shoes. I feel like they weaken my ankles. If I'm just doing bar work or bodyweight circuits indoors I don't wear any shoes at all.