Hey mates. If my opinion and advice is worth anything, it's got nothing to do with your "competition," and all to do with your positioning.
Get used to the fact that people want a cheaper price. I'm sure if you were about to buy something, you'd want to know you were getting "value for money"
Note I didn't say "cheapest price"
If I were you,I wouldn't be thinking "why do my customers want cheaper price" I'd be thinking, "why do my customers need to look around after I quote them?"
I know your good, and try everything to be professional.... but if your problem is your customers going elsewhere before committing, the only way forward is to work on yourself and your business....
I know I wasn't around for TOO long, but I managed to get enough work pretty quick....
I'm in a heavy front line sales job in your area. I know we want to stay away from "selling" and pretend that the right customers will eventually come. ... but if I could help you to close your prospective customers with your business ASAP and not have them wander around looking for something else after your quoting (which only brings your gross profits down at the end of the day) and I could help you have your customers seeing value for money in your "brand" and booking with you after one conversation and not wandering, you'd be interested wouldn't you?