Hair extension questions?

Um a hair product store called sally's carries all different kind of hair extention and etc I have synthetic hair extention but u can't curl or flat iron them but u can with real hair hair extensions um I would say synthetic hair extensions would last longer cuz mine are still ok an. There like 6 bucks and u can get 4 for 13 dollar so Sally's would b best dollar tree or maybe walmart would have suckish hair extensions a hair product store would be best