The reason they like real time is that they can offer the bare minimum, and then if I don't like it they can then ramp up the offer. If it's done via email it'

The reason they like real time is that they can offer the bare minimum, and then if I don't like it they can then ramp up the offer. If it's done via email it's basically a silent auction. So your first offer HAS to be good, because you don't know what the other bidders are bidding.