First, examine your arch. Do the wet foot on a brown paper bag test if you aren’t sure what kind of arch you have. Here’s how to do it: http://www.runnersworld.com/running-shoes/the-wet-test
Then check out shoes and prices at http://runrepeat.com
Then order your shoes from the suggested website from runrepeat.com or use this fabulous and usually the lowest price ever site:
Lastly, replace your shoes before the tread wears out — usually every 4-6 months –or risk an injury. Buying new shoes is cheaper than knee surgery or plantar fasciitis.