When anyone ask me to make him or her a quilt I tell him or her they can get something cheap a walmart, on line or any department store. If they insist, I then spend thirty to 45 minutes talking to see what they want. Whoever gets the idea just how much work it will take. We agree on a price, which is to be paid when the quilt is finished. I let them know it's pay in full at pick up, and cash. If they change their minds, I'm fine with that, I'm always trying to build up inventory for a craft fair.
And at last I think people try to take advantage of quilters is because you seem to use the words made with love a lot. A commisioned quilt is a business transaction. The word love automatically gives customers the idea that you can't put a price on love, and will put as small a price as you let them.
When quilters begin to think of themselves as business people during commisioned pieces, people will start to treat them so.