My sister and I like to make our own ears! Wire ears are easy; fabric ears are a step up.
The Dollar Tree has flower wire and lots of fake flowers we decorate the headband with. Cute, unique ears for under $10 ($5 is doable)! There are lots of tutorials online.
Fabric ears are slightly harder to make, but I'm very happy with the two pairs I've made. There are sew and no-sew; tutorials are online for each!
I love making my own ears merely because of how fun it is! The characters tend to appreciate them too and will often comment on them. I had Spider-Man sign a themed pair of my fabric ears and he loved them.