I have makeup brushes from Sigma, Mac, Ecotools, Elf, etc. I don't use the higher end brands on other people when I do their makeup, especially face makeup. I have personally found the best Elf brush to be the Studio Powder Brush (3.00), the other ones are usually a hit and miss for me. Another good face foundation brush are the Ecotools Foundation Brush (5.99) and the Ecotools Finishing Brush (included in kit that retails for 14,99) I use the finishing brush as a stipling brush, and it works flawlessly. On the higher end brand I use Mac's Duo Fibre Face Brush (42.00) the most and Sigma's Synthetic Kabuki Kit 5 Brush set (69.00)
I haven't found my favorite eye brushes yet, so I can't help you out there. Though for contouring I found the Sigma F25 Tapered Face Brush (22.00) to be best for contouring with matte bronzer. The Elf Angled Blush Brush (3.00) is my favorite brush to apply highlighters with.
I personally prefer higher end brushes for myself, but I have found that both ends have their pros and cons.