Where can be the item prices be edited in RFPOA?

I know a lot that if you edit item prices, it'll only be client-side. But i want to know where is the file that prices can be edited in RFPOA?

And in the game, If you have an item, then you sell it to NPC, it will show the sell price. And if you click ok, it will then sell the certain item with the sell price but how does the server actually know that, that is the sell price? Where can the server get that info?

Thanks for answering.:rolleyes: