A few months back we heard a rumor that said that Sony had lowered the WiFi Vita model's RAM, cutting it in half, from 512MB to 256MB. Reality Fighters developer Novarama latest comment substantiates that rumor.
"It's actually good for developers to work under constraint," Novarama CEO Dani Sánchez-Crespo told Develop. "Generally for Vita, we still have a whole lot of headroom in terms of GPU power, CPU power and, indeed, RAM."
The developer reminds us that the original PSP only had 32MB of RAM.
Perhaps Sony cut back on RAM on this base model to get the starting cost lower to fight against Nintendo and their 3DS. The newly announced 3DS price drop from $249 to $169 screws that all up, though.