I have a MacBook Pro 17" 2009 Core 2 Duo.
8Gb Ram, SSD.
Logic X is working great with up to 60 Tracks per Project, and tons of Plugins. Stable as a Rock. My Protools 10 was never so rock solid with so many tracks.
For 500-800 Bugs you would get a great used machine which handle logic like a charm.
Try it out. If it is not the real thing for you, you could sell it with minimal to none loss again.
If you find Garageband intuitive then you would love Logic.
I hate Garageband because of the not intuitive workflow