If I was looking for a bike purely for commuting, and I was intent on buying new, I'd get a hybrid for about £400-500 from
Decathlon or
Halfords or somewhere like that. Or I'd get a Brommie (oh, I already have one

) and you
know you are paying for swankiness and foldiness there.
Comparing aero bikes with mopeds is a bit weird. An aero bike is for sport cycling, whether its racing or bragging on Strava. A moped isn't (unless you are a sneaky cheat)