Locking entered values

Generally, there seems to be a push for us administrators to lock values entered in CRMOD to forbid users from changing values at will (data integrity).  There is also a requirement to document historical data. 

As an example, if a user enters values (say, business terms for a transaction) then they have to revise those terms as the negotiation continues  -- there is a push to have a historical documentation of the original  terms and then each subsequent revision, if any.

One proposal is to lock the original terms once entered.  If there has to be revised terms, the original record is escalated to Closed/Lost stage.  Next, the user will have to create a new record with the revised terms.