While shopping today at the Building 19 in Burlington for open cell foam (2 1/2 inch thick by 12 inch round was 2 bucks) I decided to look at the Men's clothes. They usually don't have much in my size, but you never know what you'll see.
I saw an entire rack of Trenchcoats. from size S to size XXL (Yep, I'm a XXXL though that will be changing in the coming year). They were all the same Sand/Tan color. Not a brand name but decent quality for Building 19
Now for the good part...$29.99. If you need a cheap trenchcoat for that P.I. character, this is a good place to look.