How much money will it cost for a new combi boiler and wider pipe work?

[ihatethecold]

I live in a 3 bed cottage that has crap heating.
Half the rads don't get hot.
The new radiators that are nearest the boiler are very efficient.
I have had the rads balanced to try to even out the heat.
The boiler man told me that the pipes are not wide enough to cope with the extra rads that were put in when the house was extended before we moved in 10 years ago.
We will get a new boiler in about a years time but I'd like the pipes to be replaced also.
Am I talking thousands and thousands to do this?

We've just had a quote for an Ideal combi boiler, updating our narrow microbore pipes and two new rads for about £3,200 including all parts and labour. We're in the Midlands. We could have gone for a cheaper boiler (a Valliant) but opted for the Ideal.

We shopped around but couldn't find a quote for much less than £2,500, and that was with the cheaper boiler and no new rads.

Thanks.
Is that updating the pipes throughout your house?

Sorry, hadn't seen this reply. Yes, although the pipes in the newer part of then house don't need replacing (kitchen, bathroom - single storey extension)

Thanks bo.