[help needed] Vendor for Emblems


I am wondering if it is possible to create a vendor script to exchange 10 Emblems of Triumph for 1 Emblem of Frost?

In the wiki i found npc_vendor table (wiki-link) and extended Cost field.
But i think there is no entry in ItemExtendedCost.dbc having this item at this rate a item cost, correct?

Is it necessary to create a script for it?

Or would it be possible to look at the vendors in Dalaran which sell Tier10 armor?
And copy and edit an entry from there?

Any help to get started on my own is appreciated.
And solution will be published if allowed.
It is a learning project for me and my non-public test server.

you cannot use any value, you need to use existing values.

okay, i expected this.
Because dbc’s are clientside.

Can you imagine a simple custom script like:

if 10 or more “emblems of triumph” in character then:
remove 10 emblems of triumph
add 1 emblems of frost


Maybe - if easier - a gossip menu instead a vendor item that runs a custom script like this?

Thanks for the reply!