The way I look at it is this.
Each tradesman is different. I have got jobs where I have not been the cheapest but I am a known quantity. My work tends to speak for itself. The customers are happy and recommend me. Also I tend to gel with some customers from the outset.
The next tradesman will essentially offer a similar but different service. He may sware like a navvy, not clear up after himself etc etc. Also he may either do uncessecary work or cut corners. A lot of customers know that you won't get an identical job from 2 different tradesmen.
Sometimes I do lose out on price with people who know me. One builder in my area regularly undercut me and some other tradesmen for a while. I decided to let him have the work until he got booked up with cheap work, then I started getting work again. He seemes to have stopped doing that to me at least.
I have been haggled on price and I know that the other 'quote' never existed but I agreed to match it knowing that i could still make good money and the customer would be well disposed towards me in the belief that she'd got a good deal.
When you buy product, a bag of Weber SLC is exactly the same whether you buy it from CTD, Topps, independent or whereever, so as a tradesman you are comparing prices for the same product from several different suppliers. So it makes sense to keep an eye on prices and make sure your loyalty to one supplier is not being abused
Also, suppliers tend to get repeat business. Some of us tradesmen do but often, especially for those that just do tiling, you'll get one job or a couple of jobs from a customer and that will be it. As there is only so much tiling you can do in one house :lol: