What are some cheaper alternatives to Airport Express that allow music streaming?
Unfortunately, there aren't any products other than the Airport Express that are compatible with iTunes music streaming (unless something new has come out recently). However, it's usually very easy to find a used model online for much less; I was able to pick up two of them on Craigslist for about $30 apiece. They may not be the latest model, but if all you're interested in is streaming music, then any model will work just fine.