I wanted to share my experience with two brands of brushes over the years, one very high priced and one at the other end of the scale. I often believe you get what you pay for but this doesn't seem to be the case here.
About a year ago I bought a set of a dozen or more Silver brushes, which is often touted as the top brand. The sables lost hairs right from the start and I ended up throwing them out, sometimes the very first time I used them, since the stray hairs kept getting in my painting. The Silver bristle brushes seemed to be no better than other brands.
On the other hand are the synthetic brushes from
http://www.Trekell.com -- very low priced, never lose hairs, a joy to paint with and they ship them to you almost immediately. Thanks to Bill Whitaker for recommending them several years ago. They've been my main source of brushes ever since then.