I cannot bring myself to pay for a cosmetic bag when I get the free ones when Clinique has a free gift with purchase & I have probably 50 or so saved up. Consider buying a makeup set, and right now around holiday time would be a great time to get a free gift like a cosmetic bag. Many times they even have two bags in each offer, one small & one large. They don't last forever but they are actually very nice.
How about something from vera bradley, the have a wide range of colors and patterns. The small is 20 and the large is only 26, plus it has a wipeable liner. It's what i have and i love it, plus it can be thrown in the washer and come out looking like new.
Disclaimer: Though I don't wear makeup myself...or carry a cosmetics bag (I do have a Kiehl's plastic travel pouch though, for skincare)...
I have heard people say that Henri Bendel is the best for cosmetics bags...
But I'd have to second jroger1. A lot of the higher-end and premium brands will have nice bags/cases/pouches as gwp, part of a gift set, or purchase-with-purchase. A prime example: the Coach for Estee Lauder one out right now that will soon be sold out everywhere.
What brands do you favor? If a (handbag/apparel) brand you enjoy also has a beauty line, you might be pleasantly surprised. For example: Dior GWPs are VERY Dior-esque (often using the same style charms and quilting). Burberry's new beauty line has packaging that is very plaid/check-ish, though I'm not sure if they have a pouch with any of their products. Armani and YSL also come to mind. Not too sure about Chanel though...anyways, have fun exploring!
Do you live anywhere near a MbyMJ store? If so, you should check out the Special Items -- TONS of things <$50, including accessory cases and clutches. You can see a lot of the Special Items on the MJ website, but there's even more things in the stores