For example, the authors announce a total price of provision "Wood + hardware" (Timber frame, posts, beams and rafters carriers) of 11439 VAT !! It is clear that the "sponsor" of the operation, as the authors call it, has overrated the extent of his help. I am very "surprised" that the professional group gathered around this project has not lifted the hare. Proof of disconnection of the ground.
To give an example against, I was recently on a self-builders yard. With less than 8000, they bought the provision to mount the walls (timber frame poles between beams) and the framework (tradi) from one house to 65m² floor. Proof that prices advertised in this book are 3-4 times overpriced.
I can have the same pitch on announced volumes of work ...
To conclude: "self-builders: do you good surround, multiply exchanges with real home builders, you will build better (natural and healthy) for MUCH cheaper"