Good quality brushes do not have to be expensive. If you look around you can find really good brushes for half the price of a MAC Brush.
ECO Tools Brushes:
These are by far my favorite brushes. They are very soft, and are made of vegan synthetic bristles. The handles are much smaller, which is a good thing because you have better control. They come in sets, but some of their brushes are sold separately. The prices are also very affordable (ranging from about $6-$12). Keep in mind that synthetic bristles tend to have a longer drying time after you wash them, as opposed to natural hair bristle brushes.
Studio Tools Brushes:
These brushes are sold at Target and are very affordable. Some brushes are better than others in this line, however, overall they are soft and good quality. The stippling brush pictured above is my go to brush for putting on foundation!
Sonia Kashuk Brushes
Now these brushes are actually a little pricier than the others ones above, but are excellent quality and are more on the level of MAC quality Brushes. I prefer the ones that have a black handle as they are the more professional ones.
Icing sells surprisingly good brushes, but I'll do a review on them later.
The studio line for ELF has really good brushes, however it is hard to find these brushes in stores so you have to order them online. DO NOT buy the regular line of $1 brushes, they are horrible!
So there you go. One last note, Walmart also sells some good brushes but I don't personally own any so it wouldn't be fair to include them in my post.