Not normally, usually it's three, and it usually happens in reverse to me!
Last month I had offers for two seperate items, both of which were 50% of the indicated price, oh and he wanted me to wait 10 days to be paid....
You can guess what I did.....
But seriously if you MUST have it, I would choose your best price, ie the maximum price that you are comfortable with, and take it from there.
Plenty more fish in the sea.....