You didn't do too bad. I've recently seen guys trying to sell that style for $25-30, maybe more on the Bay recently. Plus it looks like it is in very good shape.
I'd like to see some good info for determining the age of these brushes as well.
I think the price was fair given its condition. It looks unused. IMHO it's one of the prettiest vintage brushes, a classic design.
Edit: You were asking about year of production. Brushes are difficult to date. I think this one is 50's because it's not made of bakelite or catalin.