Will arch support help me run better?

[Ariel A]

i did that one foot arch teller thing at walmart where it tells what kinda arch u have. i have a low arch (nearly flatfooted) and i was wondering if get arch support, will it help me run faster/better than i do now? im in cross country and i run pretty decently and have a good sprint. but, when i run for a long period of time, i start to feel my arch kinda collapsing i guess? like i feel more flat footed than normal after running more than a mile sometimes...idk sorry i cant really explain it. xD my friend is flat footed/low arched too and she has arch supports and shes the fastest on the team. will the arch supports help me and is it worth $50 at walmart? xD Thank you :3