I don't know if I'd pay for a game that still bases some degree of it's fun on the likelihood of running into another 3DS in Nap Town.
When you exclude conventions and my two friends with the console, I've had maybe 3 Street Passes in this city. I'm partway into Find Mii 2 based entirely on rehiring Scott Moffitt and one of my friends with a blue shirt with my play coins.
Still...I must admit I'd be pretty stoked if I was finished with Find Mii 2.