I'm interested in buying a new MBP 17" and wanted to know what I might expect to be able to sell it for in one year, provided it is kept in excellent condition. Should I expect to be able to sell it for only half of what I paid? FYI... I'm someone who likes to upgrade yearly. I'm looking at eBay and the prices for used MacBook Pro 17's are all over the place - I see anywhere from $900 to $1200. For a notebook that is originally $2400, that seems like quite a lot of depreciation.