On all the online and high street shops this is the best value. Even better than buying from the console itself.
Ontop of that this specific (4200) points card is the most value for money on play aswell.
1600 For 13.99 that's 114.4 points per pound
2100 For 16.99 that's 123.6 points per pound
4200 For 32.99 that's 127.3 points per pound.
Now its not that much cheaper but it adds up. And points can be used for many things.
Rent some classic or new movies.
Buy some old school arcade games.
Buy some new arcade games.
Personalise you dashboard or gamer pictures
Expand the experience of some games. Dlc
Dlc includes many things. Such as songs for rock band / guitar hero. New characters, new maps, new weapons, new cars, the new gta iv add on "the lost and the damned"
Points are extremely usefull, and you will find it very difficult if not impossible to get better value for money on here