I have a few questions about buying an MBP: Do the old models of MBPs see a price drop as new models approach, or once new models are officially announced with release dates? If so, how much of a decrease in price do they usually see? Are the previous models (specifically customized builds) still available for purchase once the new models are released, and if so, for how long? Does Apple offer any sort of trade-in program for MBP owners looking to upgrade to the newest model, or is the Apple Recycling Program the only way to "sort of" do this? Thanks!