Extension roof and truss layout ideas

Hi all,


We're planning an extension of our early 2000's house. Brick veneer, colorbond roof.
The original roofline is painful and we're having difficulty coming up with budget friendly options to extend.
Attached are existing and current proposed plans. The builder we have been talking to is saying that doing this roof will mean all the old trusses etc need to come off and get completely replaced - big $$.

Can anyone see a way of doing this that doesn't need to have all the trusses taken off?