Most I've spent on concert tickets are about $80, that was for Coachella 08 but the best thing you should do ,is to compare the prices . you can do it here:
http://www.ticketwood.com
$90:70
about 450!
109
$17.00-75.00
$5
Tickets are €45 on O2 website
It depends on where and when the concert is being held.
100 dallors
$ 1
$5
£40-£90
£100 or depending on the concert