nope.
banded wheels are legal, the same as a cracked alloy being welded to repair is legal, so long as the wheel is up to the job and not in an unsuitable condition, i.e. welded by someone who has never done welding before.
if your going to go for banded wheels, don't go for cheep ones.
to give you an idea of cost, just to get 4 wheels banded should cost you £200-£300.
in reality, a set of banded steels don't cost much less than an average set of alloys.