The work is done and was never priced

The instruction came on a phone call or in a site conversation, the work was done the next day because the job needed it done, and the pricing was parked for when things calmed down. Things did not calm down. Now the change is concrete and the price is a memory exercise: the hours were never recorded as dayworks, the operatives have moved on, and where the extra work ends and the original scope begins is already going soft at the edges.

The value did not change with the delay, but the evidence did, and it is the evidence that gets paid. A change priced in the week it happened draws on records that still exist and a memory still fresh, in the form the contract asks for; the same change priced months later is a negotiation held on the other side's terms, because the burden of proving it sits with you and the proof was never captured.

The backlog does not price itself, but it can still be priced properly: what records exist gathered up, the build-ups done to the contract's rules, and each item submitted while the account is still open.