Dunno if you get this specific sales in the US PSN Store too, but I bet my hat that there's a CrossBuy Sale on there as well. I just got Hotline Miami (4$), Knytt Underground (4$), Guacamelee (9$) - each for both PS3 and Vita, as the name suggests. There's lots more on sale.
Flippin' sales really push my buttons. Below 5$, there's almost no resistance to a purchase anymore. Bigger games go that way at around 10$. Still hate myself that I didn't pick up NFS The Run for a tenner in the Summer Sales. That 4 hours campaign would've been mighty sweet at that price.
Bloody hell - nobody has the time for all this anyways!