Can you give examples of what those important functional roles are?
I don't see why prices would rise, no-one uses the cost-plus method of pricing anymore
08xx numbers route to geographic numbers.
08xx number can have their routing changed on the fly.
Geographic numbers are what they are.
So a prime example would be exactly what I delivered 2 weeks ago.
A large redesign of the IVR/call flow took place, pretty much a total revamp.
It was set live, and the 08xx numbers that route to the old design were rerouted to the new one. People calling the 08xx number get the new design without us or them having to do anything else.
People using saynoto0870 to get the geo number will be calling the old call flow, which no longer references the correct call centre skills and it badly design (legacy crap from before I started working here).
That geo number will also go back in to the telephony pot to be recycled and used for something else in the future, but people using saynoto0870 will keep calling it, making it pretty much a write-off.
Think of 08xx number as domain names. You can make all the changes you want on the back-end of the website, and people will just keep going to the domain name and experience the changes.
Also, geo numbers are a right pain to report on compared to NGNs *glares at BT*.