I just bought two 50's dress patterns by Butterick from Joann's for $1 each. There were around 10 different dresses, but sadly most of them were out of stock in my size at that moment, which sometimes happens when patterns are on sale.
Watch the weekly sales flyers for Joann's. They have $1-2 pattern sales by brand all the time. Also, I totally recommend just going to Joann's and planting yourself at the pattern book table and just flipping through each brand's book and writing down which ones you like. I always collect pattern numbers then wait until the brand I want is on sale for $1.
And personally, I've had horrible luck with Burda patterns. I recently bought one of their patterns and was more frustrated, and pissed off, with their lack of instructions than I have ever been with any other sewing pattern.