Almost perfect - what should I do?

I found them! The perfect boots for E's Halloween costume. Well, almost perfect. They are a little tight around her legs, but she didn't seem to mind. She was running around in the store with no problem. And the other ones we've tried can't even be zippered even though I tried a size 7, which is 1½ size too big and she can't walk in them. So I would say these fit pretty well. The other problem is I payed more for them than I would pay for a pair for me (I am cheap though, so don't think I spent a fortune).

Here are the reasons I bought them...

• They actually fit.
• I have 90 days to make up my mind. I can always return them if I change my mind, but at least I have them as a back up. ( I always wait with buying things so that I'm sure that I want them and when I go back to the store they're gone.)
  
• I love what she's going to be for Halloween. This might be my last year deciding. Next year she will be almost three and might want to pick out her own costume. And little girls tend to pick out the cute princess costumes. Not my style. I might as well splurge while I like the costume.
• She will be SOOOOO cute.
• They actually match some other outfits she has and can be worn before and after Halloween.