I think I'd allow items like that.

Can be fun... Or risky if it's your only means of healing. Which can be fun.

On the other hand, prices I need to study and decide.

Do I have enough support for this to ask Lugio?

EDIT: Also Lien was based on rupees from Legend of Zelda, lien meaning "link" in French. If it was equal to Japanese yen, we were receiving 10-20 USD or AUD equivalent from missions.