Just don't buy them from any other site apart from the official sites, as they will sell re-sale tickets at the face value plus the booking fee.
You are merely feeding the touts. The tickets are expensive enough if you are at the back of 80,000 in Heaton Park. They really are fleecing their own Mancunians, standing only tickets and they are all £150 or more.
Don't get the FOMO feeling just because everybody else is going ape over tickets.
Have seen most of the big bands and singers over time, some already RIP, and never did I think then that they were over priced.