Let's put an end to buymugging once and for all. Similar to how new players can't be attacked let's put attack protection in for the sellers. The way it would work is once you buy something from someone you and everyone on your friends list would be prohibited from attacking them for the next four to six hours depending on the price of the item you bought. I say four to six hours because if they haven't protected the money in that amount of time then that's on them.
Now you may ask what if they start an attack. Buy the thing. Then go back and finish the attack they already started. Simple, base the amount that can be mugged on the cash on hand at the time the attack button is clicked. Once the attack is successful the mug click would then determine the percent of the cash on hand at the time the attack button was clicked to pay out to the attacker as normal. I considered putting in a change so that if you are currently attacking someone you cannot buy from them but that seems overly complicated for what needs a simple solution.
*Edited to add the friends list to those prohibited from attacking to deal with the have my friend buy while I mug thing that I was made aware happens.