Some Vita Games May Require A Memory Stick For Saving
Yes you read that right, some games will not be using the Vita game cart for your save file (read: the ones you download digitally).
It might be wise to purchase a memory card if you are getting the system. There is no built in memory like a PSPgo, so if you are going to be buying lots of games from the PSN store it will be a must.
Here are the RRP prices for the memory sticks when the system launch this December in Japan.
So by my guesstimation you will be dropping around $20 for the cheapest one and probably closer to $90 for the 32 GB model. Seeing how I love my PSN games, I will probably be using the money saved from getting the Wifi model to buy a beefy memory stick.