One bright spot in the otherwise rising memory prices (eg Mac Pro) is that you can now get 8GB for your MacBook Pro unibody at OWC for under $500. Apple charges $1000 for 8GB, so that’s a huge savings. OWC will also take your existing 4GB for $45 cash-back (4GB eg 2GB modules are worth little because they use readily-available lower density chips).
Don’t have a MacBook Pro? Get a refurbished one and save 15%.