In haircare, I don't think regular or extra virgin makes a differnce. Extra virgin doesn't go through the refining process when they press it, this leaves more color, more flavor, and more solutes in it. This therefore it has a lower burning point, thats why its not to fry with, but to use like drizzling on salads. Regular olive oil gets refined through thr press more times, taking out flavor, color, and making it clearer since there is less solutes floating around. This therefore gives it a high burning point, and this oil is used for frying and other cooking needs.
As for hair, all oils coat the hair strand, whether it be extra virgin, or regular. There are no extra nutrients that will be picked up by your hair by using extra virgin.
(if there is it is negligible compared to the whopping price of extra virgin)
So my advice is stick to regular and get it bulk at Costco or Sams Club for cheaper. And spend your extra cash on indulging your PJism somewhere else.