If you want to compare the "per property" cost in the BT funded and that in the subsidised rollout then the central infrastructure should be removed as they will be common across all.
A simple version:
£1m on infrastructure.
£2m to provide say 100,000 connections.
So, that is £30 per connection.
The subsidised contract to roll out another 100,000 costs say £3m - or also £30 per connection. That is the first thought and it looks as though there is no difference which is what the figure look like first off.
You can then look at it two ways: If you exclude the initial infrastructure cost, the first set actually had an incremental cost of £20 and for the second it increases to £30.
Or if you amortise the initial cost over the two sets they come in at £25 and £35
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