Constant problem for me when I ran a militaria shop. Number 5s sometimes went for fancy dress (I had one female client who bought several mess kits from me, including RAF and various army types) but number 1s of recent vintage were pretty much unsaleable, so I tended to turn them away. I could occasionally sell an officer's greatcoat but at a pitiful price when you considered their cost new and the superb quality of the material.
WWII vintage uniforms, particularly with wings/medal ribbons are a different matter, but I'm guessing DH's dad's uniforms don't come into this category.