I really dont think it is a problem comparing thier prices to your's or any other company for that matter.
I mean Asda and Tesco are always trying to out do each other on national tv adverts and magazine ads etc. So i dont see there being any differance here!
But the thing is, do you really want to even mention another carpet cleaning company on your site?? i wouldn't! gives more places for the potential punter to ring around for "quotes" your local Chempooe might be great at closing the sale etc.. even tho his prices are higher!
I'd stick to just saying your better priced than the bigger companys cos your overheads are lower and dont have to pay royalties etc etc like was mentioned further up the page.
my 2 pennies
cheers
tony