SEGA has sliced the prices of some of their old PSP games on PSN permanently. Here’s a list of the games with their original and slashed prices:

Alien Syndrome: $9.99………$4.99
Crazy Taxi: Fare Wars: $9.99………$4.99
Crush: $9.99………$6.99
Sonic Rivals: $9.99………$6.99
Sonic Rivals 2: $9.99………$6.99
Super Monkey Ball Adventure: $9.99………$4.99
Valkyria Chronicles II: $19.99………$9.99

These price cuts do not apply to Europe (at least not yet). Because these games are being sold on PSN they can also be played on the Playstation Vita.

[Source: SEGA Blog]