Why don't you look at it this way? It's more expensive, but much better value for money?
I don't think you should miss this opportunity to update your equipment.
After you have tried it out, I'm sure you'll agree that this is a very good product.
You're right to be cautious, buy owing to the limited supply available at present, we suggest you act quickly.
I don't want to sound pushy, but you'll have to decide soon.
Could you think about our proposal again?
Could you reconsider the matter in some other light / from a different angle?
Isn't there any way to change your decision?