Maggie seems to think we should start saving for horse equipment. I'm working to sway her toward more economical interests, especially as long as her interests change so frequently.
So far the only horses around here are her tire swing (which sadly hasn't been hung up yet, as there are no trees appropriate in our yard, and while I have a great idea in my head, it hasn't been executed yet), and a Barbie horse. Barbie (or Barbie's mom, or the bad lady Barbie, or the dentist Barbie, or...oh, you get the picture..) rides nearly every day. Usually to or from her 'marrying.'
I don't think Maggie has realized yet all the other accoutrements that come with horseback riding. Once she does, the lesson of cost vs benefit will be close behind. There's some other cool stuff left to explore that can't be undertaken at the same time as the investment in horsies.