We use Zoho books for all of our estimates, and probably in 50% of cases the final PO is not exactly the same as the initial estimate-.

There are many cases where we go through a few revisions of the estimate before reaching the final situation that the customer places the PO. Or sometimes the quantity ordered is higher or lower than the quantity estimated.

However, when we make changes to the estimate the information about what we originally quoted is lost

It would be nice if there was a way to make revisions to an estimate and keep a version of the previous one.