I don't think any of the girls have worn the same outfit twice. It's because they have a different clothing brand sponsor every episode. Besides their school uniforms, senshi clothes, Rei's miko robes, and Usagi's pajamas, I don't think I've seen any outfit outfit on them more than once. I've seen Mamoru wear the same jackets, but that's it. I've decided not to think about it because it was driving me crazy how much they'd have to spend on clothes.