Where is your foot on the pedal? The pedal should be under the ball of your foot, not under the arch. Position would be contributing to your foot pain - but I believe that tennis shoes are a contributing factor too.

A stiff-soled biking shoe should help. Biking shoes come in all price ranges, and shops often put a sale price on last year's models so maybe you can find something that fits (somewhat) into your budget. I'd recommend a trip to your local bike shop to see what is available.

--- Denise