Creating an item that lowers cost to purchase items

Needing to find out how to make two different items.  One to lower the cost of an item by say 25% and the other would be to increase the sell back price by 25% so you make money on it.

it sounds like you need an event bound item, like the guards pass in the legend of Zelda that gets you the Hylean Shield cheaper than the original price, this would probably require a script that has a variable system, where you add a script note to the item in the database and it activates the script


but don't ask me to make it because i cant yet. i'm still waiting for the simply ruby tutorial to finish up, try asking modern algebra, he has some really good scripts and maybe already has one that's close enough to what you need.

Anybody else have any advise on how to do this?  Cause I'd like to get this to working before I finish the game without it.