You can purchase badger brushes from $20-30 all the way up to several hundred dollars. It all depends on what you are looking for in a brush.
Do you mostly lather creams and soft soaps, or are you partial to triple-milled pucks? If you like hard soaps, then you will probably want a brush with more backbone. If you use mostly creams and softer soaps, a floppy brush will work well.
What sort of face feel do you like? Do you want your brush to have very soft tips, or do you like some scritch? A black badger is likely to be scrubby/scritchy while a silvertip is soft. Other types fall somewhere in between.
I like my brushes to have some backbone and to have very soft tips. So for me two-band finest and densely-packed silvertip brushes work best, but they tend to be pricey. I tried black badgers and pure badgers, but they irritate my sensitive skin.
If you purchase a brush that someone else loves, you may be disappointed as their needs and preferences may differ greatly from yours. Figure out what you need in terms of backbone and softness vs scritch/scrub and then try to find a brush that that will match your preferences and yet fit within your budget.