I'm dithering between getting a house desing via an architect, or going with a TF company who will do design&supply.   I'm nervous about going with desing&supply basically around cost: if we get a design done with TF company A, expecting to use them for supply&erect, how do I then check that their cost for the supply portion is going to be reasonable? While of course I can set a maximum budget for them, presumably they'll simply aim to charge that amount. However, asking th