The best thing to do is to stay calm and listen to exactly what their issues are and then explain the merits and advantages of the products that you have. This is very important to have good product knowledge so you can let them know what they are missing out of if they don't take it. So basically if you can explain it calmly and list the advantages, they will be able to see and everybody does like a better value. I know price would be like the first thing they think of. If they give it some thought, it's something that is very important and they would be missing out on it.