Some people are hardcore about their dirtbikes. They will ride nothing but quality, the genuine article from one of the big manufacturers like Honda or Suzuki.
With the popularity of any sport or pastime there always comes cheaper versions. Not always as good in quality but another way to enjoy the fun.
Pep Boys dirt bikes are just that - a cheap alternative to mini dirt bikes.
They say "if you pay peanuts you get monkeys". In this case if you pay half the cost then don't expect the same quality, service or back-up of the big brands.
Just have fun... while it lasts :P