Priority Club made changes to what points count towards elite qualification on January 1, 2013. I wrote an article about this change back in December. Until the end of 2012, all the points earned from various bonuses and partner activities had continued to count toward the requirement of Gold or Platinum status.
Base points earned from Qualifying Rates paid for hotel stays, points collected from partner transactions, PCR Bonus Points Packages and Meeting Rewards are considered Elite Qualifying Points and counted towards membership elite status.
Priority Club used to count points purchased through their Points & Money reward option towards elite qualification but discontinued it.
Points purchased through Buy Priority Club points used to count towards elite qualification and they still do.
I did the following test this week. I purchased 1000 Priority Club points (the maximum that you can buy is 50000 and the maximum you can be gifted is 50000) through Buy Priority Club Points that is handled by Points.com that handles the back end for many loyalty programs that sell points to their members.
The points posted couple of days later after the purchase and they still counted towards the qualification.
This is not the cheapest way of purchasing Priority Club points, but it can make sense as they still continue to qualify towards Gold/Platinum requirements.