I've tried setting it in the config and doing the commands for it:
/mvm set price 25 creative
/mvm set currency 388 creative
but nothing seems to be working. When I go through the portal in my survival world I want it to charge 25 emeralds to get to the creative world. The problem is that it isn't taking any emeralds from my inventory when I go through the portal. I don't know if this is because I'm oped or not, but I know it should be charging me that entry fee.

Could you provide the link given by /mvv -b --include-plugin-list please.

https://pastebin.com/Ng1Nwn3D

I think the issue is that your economy plugin doesn't support Vault. Unfortunately there's nothing we can do about that 🙁.