If not derail then just to get a ton of valuable business insight that isn't available publicly. A while ago a large software company dragged us through this process for months, and eventually backed out at the last minute. A short while later they had a complete clone of our service ready for launch.
Large mergers use 5% of the purchase price as a backout fee so the cost and waste of time is assigned back to the initial party. Still wasteful.
In the best position, I would assign a price as is no insider knowledge given. If they are interested they will buy because they already have research done prior.
