the is no patchs in this business, the people who claim there are, are scared of losing work, if some one asks for a quote then so what quote them, the only time it is a problem is when u know the price of a job and go up to the custy as offer a cheaper quote, that is when people get upset, but like you say it doenst bother other business,
for example if i put a flyer out offering any house for £6 loads would moan that they might lose work, but from my point of view it would make good business if i picked up a load
the way i look at it is no one is bothered if they take jobs off you, look at what is happening with national contracts, so why shoudl you be bothered about taking some one elses work