I agree with lots of the above posts. Having spent literally thousands on my makeup and hairup kit over the last few months, i've done my fair share of research!
Crown brushes are good. I haven't any myself, but my trainee got them thru college, and they are good quality.
Royal brushes are a fantastic cheapie option. Especially for kabuki and smudge brushes.
I have mainly...
Estee Lauder - The quality and look are second to none. Beautiful quality, hardly any shedding. Also estee lauder is MACs parent company, so you can be assured of quality.
Benefit - Lovely quality. Don't buy them all though.
GOSH - Great for a cheaper option, and can also be bought on the high street, from superdrug. Their Foundation brush is super soft, doesn't drag, and can really give the mac 190 a run for its money. At 10 its less than half the price too.
MAC - Well. I am a Macaholic lol. If you can, you should! Mac brushes are very expensive, from about £15 per brush, So what i'd suggest is getting yourself kitted out in a cheaper option, a crown set perhaps, and then start replacing your favourites/most used brushes with MAC alternatives as you start earning off it. Be very wary of ebay and elsewhere online for brush sets, esp MAC ones. Its very rare to get a set from MAC, ebay is rife with counterfeit. Not just MAC, but smashbox, bobbi brown etc too. It may seem like a too good to be true bargain when you see these sets, but thats usually it, they are usually too good to be true. I've been stung myself!!
For extra help on makeup go on Specktra.net. A dedicated makeup forum, they really know their makeup stuff on there, and you'll be surprised what you'll learn!
hth x x