It became available on the AAMC website today. It is discounted from $25 to $17.95 if you buy it between now and April 17th. Since the cheapest shipping option is $8, it comes to $25.95 total (or $33 when it's no longer discounted). Amazon has it for $25 with free shipping, but it says that it will take a month to ship (as opposed to a few days with AAMC).
I think it has a lot of good information, but if your pre-med advisor will let you spend a lot of time going through his copy you can save the $25. It's really up to you...