If you're worried, go with the Post office for homephone only. They pop the £120-ish connection fee on the first bill, but thereafter you're only in a rolling monthly contract. Twinned with free weekend mobile/international calls, it kicks BT a bit!
But yeh, it's tough to avoid that fee sadly. You might have the line at your house, but an engineer might need to go connect it at several points along the streets. Grr!