Obviously you haven't sold yourself to the aircraft owner. When the owners think that all pilots are alike, you are simply a commodity to be bought and sold at the cheapest price.

When you have sold yourself to the owner by being able to get him to his destinations safely, efficiently, and with minimal fuss, reminding him of the time where you dropped everything for that last minute trip, where you pulled the rabbit out of the hat and made something happen that one not as committed to the owner as yourself would not have tried, the owner needs to know this.

There are plenty of pilots that will fly broken, illegal, unairworthy junk for free as they do not value the owner nor themselves. Remind the owner of this. Remind him that you know of several pilots who'll do it for free and can refer them to him. Remind him that if he posts an ad anyone that ever dreamed of being a pilot will be contacting him. Remind him how hard it is to concentrate on flying when one is wondering where the next meal is coming from, or how one is going to shuffle funds to pay the creditor that is screaming the loudest, while others go unpaid. Also remind him that the types who'll do it for free are gone the second something else comes along, and he'll have to continually retrain pilots to do things the way he wants them done.

And, if the owner decides on someone else, walk away knowing you didn't market yourself enough after the sale (being hired) and resolve to do better next time.