they pay more then that
BT may only make �1.50 profit on LLU ports but that doesnt mean you can claim thats all they pay.
As I posted on the news page, LLU is a success because of a combination BT's greed and ofcom's incompetance. BT central prices have made ipstream uncompetative.
I can think of quite a few things BT could do in deregulated areas that would give LLU a hard time. But they all involve BT losing profits so I can see none of them happening. Plus if BT were to make ipstream more competative in deregulated areas I expect the ipstream retailers would use it to subsidise villagers anyway keeping ipstream uncompetitive.