I was going to mention Bushnell as probably the main brand that is going to fall into your price range.
Take a crack at eBay for that price range. If you don't mind buying used, you might be able to get better glass. Quite a few birdwatching enthusiasts sell their old scopes when they upgrade their equipment.
I bought a cheap Tasco during a Bass Pro sale for $30. It's one of their Xmas promotional items. It has zoom and is a 15-45x50. I'm going to try it out tomorrow for the first time, and I'll let you know how it works out. I don't think, however, this scope would be very good past 100 yards. The range where I shoot only has a 100 yard rifle range, so it's really all I need right now.