Depends on what you mean by a last look?
If you see some elses bid before an announced bid time or are allowed to make a late bid after a bid opening in which you know your competetion price, that is defenatly NOT ethical. Depending on your states laws it may be illeagal.
My belief is that a bid goes in on time in a fair and honestly run bidding process. If you are late you lose out unless the reason for your bieng late are truly beyond your control. And if you are the low bidder the job is yours.
If I discover that a general contractor or owner shops my bid, they will never get another one again.
I have told a couple of GC's that I am not another EC's estimating department.
If you go along with bid shoping, sooner or later that GC or owner will shop you right out of thier projects or even out of business.
