i might do the 5$ UMD transfer or whatever is the name of it
Pretty sure the UMD transfer is Japan only. Any PSP games purchased on the PSN then can carry over (if they're officially supported, anything not officially supported can only be transferred over with a PS3).
Also, I dunno how pricing is in your region but Vita games aren't better priced necessarily. 3DS games are mostly baselined at $40 where I am. Vita games range from $30-$50 (only $50 game currently is Uncharted). Still, I wouldn't see Vita games being that much better priced, if at all. EDIT: Plus the Vita itself is a pricier console, although you bought your 3DS for the same price so this doesn't really matter at this point.
All these aside, I'd say the Vita. It's really pleased me. It feels very sleek and doesn't really have "compromises" like the PSP had. It can do games that look practically as good as PS3 games, has two actual analog sticks so you can play dual analog games, and it has the touchscreen and other things to compensate (or even give it an advantage) over the few buttons its missing.
Game library is slow growing but the launch line up is rather fantastic and should keep you busy for a while. Plus it's already got quite a few good "time sink" games that'll keep you busy for a while (Dynasty Warriors Next, Lumines, Disgaea 3, etc).