Grep style prices

Actually, I don't think a GREP style is what you want here.

I say this because GREP styles (or any style) cannot add or remove text, ony change formatting, and I beleive you need to remove the . in the price as well as apply superscript to the two digits after it. I say this based on what is conventional in US, and if you are in another locale the rules might be different.

If my premise is correct, you should be using Find/Change.

Find (\d+\K)(\.)(\d{2}) and change to $3, adding the superscript formatting in the change format settings.