Same here.I've been told several times in my life that to get "the deal of the century" I need to sign now.
Again, same here. However, I do usually ask them something along the lines of "I need to think about this / talk to my wife / whatever, and that will take a few days. Does what you say mean that if I call you next week, you won't be interested in selling me the product for the price you have mentioned today?".I have always refused.
That has almost always elicited a reply along the lines of "Ah, that might be different. Call me next week and I'm sure that my manager will allow me to sort something out for you"!
... but, of course, I've never 'called them next week'
Kind Regards, John