Abused a minor detail the DM forgot about.

So we were sent on a quest and it was agreed upon by the gnome king that they would cover the cost of arming us before going to fight a lich. So what does our party do? Enchant our gear and when the DM tells us the price, I tell him that the king said they'd cover getting us armed for the fight. So we spent hundreds of the king's gold enchanting our equipment and buying other various things. The DM, while flabbergasted, allowed us to keep abusing this and get what we wanted.

I'm sure we'll get chewed out by the king later though.