Sony is launching a special proprietary format for use in the PlayStation Vita. A format that will run you from $29.99 for the least amount of memory to $119.99 at GameStop. Sony is planning on making games available as downloads which would be an ideal reason to get the largest memory available, as well as retail copies on Carts similar to what Nintendo has been doing on its poratble systems.
However, retail copies of the VITA's games carts are said to require the Special Format memory cards for regular saves as well, something you don't have to do with the 3DS, DS, GBA, N64(some N64 Games required memory cards), SNES, or even the NES. Seeing as Carts generally have had built in memory. Either way be prepared to pay Handsomely for these new VITA Memory cards on top of your retail copy of your game.
GameStop is currently listing four models of the proprietary card for preorder, starting with the $29.99 4GB and scaling on up to the massive $119.99 32GB model. If these games are as big as PS3 games be prepared to pony up for multiple memory cards if youre expecting to download your games on to the cards directly.