Urgency or not
On the difference between "I need it urgently" and "I can afford to wait", giving me time to choose the best offer at that time
It's urgently needed, so you will pay the product/service at the price you find at that moment (the sooner the better, that's why it's urgent) - Will be most of the time more expensive than in the second case. There is some extra fee to pay because of the urgency, this is part of the service
Second case; you can afford to wait for the best offer - your choice will be based on more parameters and other extra features, often at a better price than in the first case.
So, to put it briefly: urgency is more expensive but that's part of the deal