How to prevent ordinary users on the server craft coins?

i want to start a server to but i don't want to get an enourmous devaluation of ic coins
i know it was possible in original ic

Yeah

I agree with this, after a while no doupt that there was like million coins and those did not have any value.

So only admin being allowed to craft those would ease alot, as he can use those as payment as well.

go find a mod to blacklist recipies and use the /give command.

If you're using Bukkit (Which I highly doubt) Here's a link to BanRecipe: Linky
I don't think there are any Vanilla mods that disable recipes, though.
You could pass a server rule
Although, rules are made to be broken. >:D