Buckle down and get a Winsor & Newton Series 7 Size 1 or 0. Take care of it and it will never do you wrong. Good artist use good tools. I've been usin' the same 2 brushes for the last 10 years and they are still in better shape than most week old brushes I see people usin' at my LGS. Yeah they're $20 to $30 brushes, but I only spent between $10 & &13 for each one, and over 10 freakin' years of use. So you tell me if you think I got my money's worth out of them.
Here's a link to **** Blick which has the Size 1 on sale for $11.08
To get your brushes to last you need to take care of them. Use a good brush cleaner, this will get all the paint out of the bristles. No matter how clean you think your brushes are, the first time you use this stuff you will be amazed how much stuff comes out of the bristles of your brushes. This stuff is great for gettin' the paint out but it also can take the moisture out of the bristles, and just like your hair moisture is what give the brush its spring or snap, so you want to follow up the cleaning bath with a little soap down. Brush soap will remove the cleaner from the bristles and put some moisture back in, like usin' conditioner in your hair.
So after a hard weekend of paintin', pour a little brush cleaner in a shallow bowl or dish and swish/roll the bristles of your brush around for about 15 second or so until the color starts to come off the brush. Hold the bristles on a paper towel to pull the fluid out of the brush, repeat until the paper towel does not show any color comin' from the bristles. Rinse the bristles in clean water then roll the wet bristles on the bar of brush soap until the bristles are covered in lather then wash it off, repeat a few times. Then lastly put the bristles in your mouth to bring the brush to a point, and one last time draw it through the lather on the soap rolling the brush in your fingers as you do to keep the point and hang the brush bristle point down to dry, I usually run it through the soap and then lick the point but I got my mouth washed out with soap a lot as a kid so the taste of soap doesn't bother me. This will guarantee to keep a fine point on your brush for years to come. Rinse the brush in water before usin' the next time to remove the soap.
Brush Holder, just push the handle into the coils with the brush hangin' point down
The only draw back to 10 year old brushes is the writin' and hence the size numbers wear off eventually but you'll get to recognize your old friends by then.
I hope this info helps.