Go to stores that carry shoes you want outside of your town, don't spend more than $20 getting there and back. Wear old shoes you'd be getting rid of soon.
Park your car a few blocks away from the store. Go in, try on the shoes you want, ask if you can try them running outside on the sidewalk. If they say yes, run just out of sight, loop behind the store then head to your car and head home with brand new shoes on your feet. If they say no or it's a self-serve try-on situation like a big box stores, just bolt and get to your car as quick as you can and then head home with new shoes on your feet. If you live in a large enough metro area or have enough large towns nearby, you can do this once every month or two and not hit the same store twice in a year.