Sony is having a 50% off sale on the PSN:
Costume Quest $7.49 sale price; $14.99 regular price
Deathspank Thongs of Virtue $7.49 sale price; $14.99 regular price
Hoard $7.49 sale price; $14.99 regular price
Soldner-X2: Final Prototype $6.49 sale price; $12.99 regular price
MotorStorm 3D Rift $4.99 sale price; $9.99 regular price
Peggle $4.99 sale price; $9.99 regular price
Space Invaders Infinity Gene $4.99 sale price; $9.99 regular price
Swords and Soliders $4.99 sale price; $9.99 regular price
Tumble $4.99 sale price; $9.99 regular price
Comet Crash $4.99 sale price; $9.99 regular price
Shatter $3.99 sale price; $7.99 regular price
If you prefer Amazon they often price match these but no guarantee.