Wool blend dress coat on sale for $50 + free delivery @ Hallenstein Brothers
According to this merchant, their sizes are slightly on the bigger side. So if you're on the upper range of one, best to go for the smaller size. I couldn't price these up anywhere else but from what I've read online about Hallenstein Brothers' products in general, customers appear to be happy with both the quality and service overall.
This particular dress coat is made of polyester viscose (which is a common fabric in the under $500 price bracket) which is very durable. However, it doesn't breath as well as some other materials so worth keeping that in mind.
Still, this is a good price for a coat of this quality and style.