Ok, there is a shop in port sarim which sells eyes of newt for 3gp each. People tend to buy eyes of newt for a hell of a lot more because they use them for potions, hence they are worth around 50-70gp each (65 atm). Because the value of an item in a trade is the same as in the g/e, then you can buy 27 eyes for 81gp, then sell them to the other account for around 2k ish, who will then sell them back to the shop for 27gp (because they sell back for 1gp each).
Because of this, you have just traded 2k within about 20 seconds, unlike the whole 3k in 15 minutes idea.
Hope ive cleared it up

Im still going to make the script, seeing as though its simple to make and i need the experience!