Deprived, not sure if you answered this already, but have you looked into automating the transfer of PURCHASE to MINING+SELLING shares?
I did have a quick look around a few days back but couldn't find any Oauth 2 libraries I could use to do it quickly, so as I'll likely have to learn some new language to do it it'll have to wait until I've finished what I'm currently working in.
You should be able to do it pretty easily with Python using urllib2 and google's oauth2 library. If you don't know python yet, it is one of the easier languages to learn and very expressive / powerful.