It was on sale at Target for $15 on Black Friday. Maybe it will be on sale on Boxing Day or Week.
I have more than 2 towns and find it easy to manage. My main town gets played every day and extra when I have time.
Right now I'm knitting hats and just have time for my main town. To keep villagers I stopped a mover in the extra towns and wrote the date last played. Once I'm done I can go back to the date last played. The activity log will not help you with the date when you have extra town on one 3DS.
Make sure to open the copy that still need streetpass tags. If you open your new town first that town will get the tag.