You have found a category that Anazon serves, but does not serve well. I buy nearly everything on Amazon but I still have to buy her uniforms in person (each school has a specific color scheme, plaid pattern, collar style, etc.). My wife still buys her nurse scrubs from a guy who comes around the hospital and only takes cash. These are things you just can't get easily on Amazon, even though it looks like they have that category covered.

Also, you could compete with Amazon on any category just by having a bigger selection of same day delivery in some niche.