I just went to Costco, found some nice sporty metal frames with lots of wrap, and got single vision with dark tint. Less than $100.

TWO TIPS:
1. You want thin frames that sit high on your face, so that when you are on the drops, your vision is not impacted by the frame. Also the frames need to fit close to your face, without touching.
2. DO NOT buy the more expensive polycarbonate lenses, while they have slightly better impact reistance, CR-39 (aka Acrylic) is much more scratch resistant than polycarbonate.