to cut or not to cut

for the first time in my life, my hair is long. i grew up with a twin sister and to make sure we were viewed as individuals, my mom always kept my hair short and my sister's long. in college, i even shaved my head.

my point and question are about how often i need to cut my hair. i read through a lot of posts about growing out hair and one common piece of advice was to get regular hair cuts. however, my hair is growing and growing and i haven't cut it in about 7 months. i don't have the money to get my usual nice/expensive hair cut. i know that with short hair, it's worth the money to get a top-dollar stylist who can create an edgy, clean look that is not overly masculine or feminin and otherwise doesn't look awful. now that my hair is longer (well between my shoulder blades in the back) is a high-quality cut as important? or can i pay $35 for a trim by the people down the street who do my eyebrows? the last time it was cut, the stylist put some fairly elaborate layers in it. will this throw off another stylist? my hair is very thick and needs to be thinned. is this something only a fancy stylist can do well? is there really a difference between an $80 haircut and a $35 one? besides the money?

i just noticed a few split ends this morning, so i'm eager to go get those trimmed off. any insight any of you have about quality/price/fanciness of salons would really help. also, input about how often i should be getting it cut if it grows fast w/o split ends for 7+ months would be great!

thanks!