WWE released the following information today in their Q1 2015 earnings report about the buyrate for the WrestleMania 31 PPV on traditional PPV:
* WrestleMania 31 (3/29/15, headlined by Brock Lesnar vs. Roman Reigns) drew 259,000 buys, down from 690,000 buys for WrestleMania 30 in April 2014.
Source: WWE Corporate