[edit] where the heck do you live that muggings are commonplace?
Also the gov is gonna know you bought the truck when you register it, anyway.
We didn't see it as a risk. It was just a bit odd to have 150 $100 bills. Puts a little weight into the cost of what you're going to buy. Good thing he bought it too as his old truck (which I drove back, that's why he brought me not as some security) needed about $3,000 in repairs. He sold it to a farmer who did the repairs himself. My friend kept the truck for about 2 decades.
1) I remember his receipt pad. It was styled like something I imagine came out of a Dickens story. He basically bought wrecks and stuff in garages and restored some or built mods out of others. Pretty good retirement gig.
But 15k for a used truck, all cash? No thanks. I don't suppose your friend also totes a shotgun around with him just in case someone decides they want that 15k too?