Can't prove it, but it seems vendors collude in (very hot) Arizona on all sorts of necessities (plumbing, A/C, electricians). they all seem to know what each

Can't prove it, but it seems vendors collude in (very hot) Arizona on all sorts of necessities (plumbing, A/C, electricians). they all seem to know what each charges, and the prices seem not kept in check by any real competition.