I got an email from PlayStation the other day with this offer.
In the UK Paypal (not sure if world wide) is doing a office with PSN. Transfer £50 from Paypal to PSN account and get £10 off.
Expires by: 01/08/2015
hope this helps people out.
EDIT Screenshot from the PSN Store UK (showing this offer)
http://i59.tinypic.com/oj3vd3.jpg
-
maybe i will buy ttk then