Question for you weave divas, please read?

I should say I am confused. I have bought my hair locally for years and I was always told to buy Yaky permed straight by Milkyway, well I thought I was spending a good penny on my bags of hair to later find out that my weave should have lasted three months compaired to 4-6 weeks. I washed my hair weekly to later find my hair shedding and tangled by the second week. I live in upstate New York and I have bought my hair from B&V Discount and Ester's wigs. I honestly thought it was the person who was doing my braid and weave styles... until I opt for going for someone with a great reputation on doing weaves. I drove to Middletown, NY which is a haul for me and had my hair done at The Hair Studio, it was rather expensive but my hair looked great. I am now in my 4th week and my weave looks like crap simply because the hair is crap. I have read the forums and asked tones of questions but no one is answering me. I need to know what is the best hair for long term weaving. THanks