It's all a matter of perspective. How much of an issue the reduced width is depends on whether you need the extra width or not and whether 80$ is too much for extra legroom again will depend on how badly you need that extra legroom. If a seat is wide enough to comfortably accommodate you, then the difference between that seat and one that is an inch wider will probably barely occur to you, but if you can barely fit into the narrower seat and the extra inch means you fit in reasonably okay then that's probably gonna be a very very notable difference.

A skinny female that is 5'3 tall will perceive the dimensions of an airplane seat quite differently than say Shaquille O'Neal. Those are of course extremes but the general idea holds true.