How we change what others think, feel, believe and do
When they have a priority which is stopping them from buying from you, find ways of changing the priority.
Explore the criteria they are using to decide. Probe to find how important each criterion is.
Appeal to their values, which include a system of prioritization.
Reframe their arguments so they naturally change priority.
At the same time or alternatively, increase other priorities that will lead to them buying from you.
You are very loyal to your current supplier, but should you be more loyal to your family?
You are right, price is important. But how much more important is quality to you?
A big picture would look nice, but with smaller pictures you can show more of them.
When evaluating between different choices, we use different criteria and different weighting of those criteria. We also get fixated on particular solutions and forget about other criteria. If you can change criteria, change weights or remind the other person of forgotten criteria then you can get them to reprioritize.