I found this by visiting my local Nottingham AMF bowling centre, They've Reduced all their prices and if you book online you get another 10%off.
If you want to go bowling on off peak times bowling is super cheap,2 games only £7, and £1 extra for further games. so-
3 games now only £8 (Sunday 6pm- Friday 6pm)- £7.20 with booking online. (was £13)
(i don't know if the prices differ at the other centres, i just go to Nottingham)
To do it go on the site,
Select book online,and choose which centre you wish to visit. Chosse your time, amount of people , then enter in your details and pay. Super easy!