this goes back to when the adsl ports got a massive drop in prices to satisfy ofcom.
When adsl was first launched in the uk 1mbit ports cost more than 512kbit and 2mbit ports cost more than 1mbit, I think 2mbit adsl was something like £80 a month.
Ofcom as they are now like the sell em cheap pile it high product, so they persuaded BT to artifically not charge for burst speed, however BTs revenue needed protecting so they moved the cost to the backhaul, hence the very expensive BTw backhaul came about.
Since then 21CN has lowered pricing so its not so extreme anymore, but they remain more expensive likely to not been able to charge as much as they want for ports.
Edited by Chrysalis (Thu 07-Sep-17 21:18:06)