Hmmm. I still wonder how that maps to the few bits of price lists we've found before but think of it like this...
BT-Openreach have been passing on charges for "customer" broadband faults since last year and these usually get quoted at £188. So if we take your £218 and subtract that we get £30. Now the previous £25+vat would equal £28.75 so if some bit of BT (BT-O, BTW, BTR in this case) have raised it or rounded it up we get the other £30.
So basically they charge a full engineer call out fee PLUS the (inflated) cost of the faceplate when the change is to the BT boundary on the connection because it is out of date.
Nice.
The price is crazy as adslnation has the faceplate/middle/surface mount backbox set for £5.86 and that's the NTE5a with the extra filtering built in just like the latest BT ones. And that's not the cheapest even with a quick google! Even the most expensive don't seem to charge more than £10. So they are even profiteering on the faceplate!
This suggests the first extension adaption like at the bottom of this Kitz pageis the most sensible for most people.
Maybe I am missing something, but WHY did the OP's ISP decide to replace the master socket? Had the previous master socket developed a defect - or did the ISP decide to send an engineer to upgrade the socket, merely to facilitate extension wiring?
BT Openreach are responsible for maintaining everything between the telephone exchange and the master socket on the subscriber's premises. Although BT Openreach should not charge for repairing faults in
their equipment, they can (and will) charge the subscriber (or the subscriber's ISP) for voluntary upgrades.
In the case of an old-style star-wired installation, BT were responsible for the master socket in its entirety. Consequently, if an old-style master socket develops a fault, BT Openreach must replace the socket at no cost to the subscriber or to the subscriber's ISP.
However, the subscriber
will be charged for any faults that can be attributed to the subscriber's own equipment or extension wiring. (i.e. Anything that is connected on the subscriber's side of the master socket.)
If a subscriber has a new style NTE5 master socket, BT Openreach own the linebox. Consequently, they are responsible for faults in the backplate. However, it is a moot point whether BT Openreach will bear the cost, if the NTE5 faceplate develops a fault. Again, the subscriber
will be charged for faults that can be attributed to the subscriber's own equipment or extension wiring.
However, the NTE5 linebox does have a test socket in the backplate, which provides an opportunity for the subscriber to eliminate the possibility of faulty extension wiring - before requesting an engineer's visit which potentially, could be very expensive.