Hmm... seems they've all run out of the old stock. The cheapest I could find and where I buy from; http://www.prepaidgamer.com/playstation-network/
You could do that. Then chances are you might end up buying something that isn't available in this region. Afaik games are available to all users on one console but save games are different. I can't be a hundered percent certain as I've never had a need for this, I'm the only user.
*I normally just buy 3 months at a time as that's what I can afford.
