i bought some brushes off of bun bun city, and personally I think they are pretty terrible quality. If you are expecting high quality, these brushes will not give you that. They are however, cheaper in price then drug stores.
I personally think its worth the little extra investment to buy quality brushes. However, you def dont have to pay a high end price!
There are some great deals on smashbox brush sets on ebay. Although I bought my 5 piece brush set for 60 dollars (but a 125 dollar value), they are now bidding for 30 dollars on ebay.
125 dollars worth of QUALITY brushes for 30 dollars is a steal!