Different takes on approach here from Peter and Charlie.
BH is about say buying your first house/ flat, doing it up, then..maybe self building or just sitting back and saying I did that once and that suits me, innovation, the excitement and that deep personal reward you get, feeling of achievement.
I think Charlie and Peter to my mind have identified part of the problem. Charlie mentions new SE's coming in not knowing about the building regs in detail, it's a valid point.. on a social level it could be defined as the division of labour, see for example Adam Smith.. The Wealth of Nations for a bit of background.
In summary we all have become more specialised in what we do as the population has grown and now we are arguing the toss about a few quid between Architects and SEs etc. We used to draw on paper, now we use a computer.. it's just a tool. I can spend a day, sometimes more on cad just working through a detail that will last for 50 - 100 years more I hope! Before I could go through a wad of paper.
Folks on BH.. it's the thinking time that counts not how fast you can move a mouse.
@CharlieKLPbut the same can can be applied to young Architect's and other young designers. It's not their fault that they maybe have less intuition about how to realise their designs economically so that they will actually get built.
My advise to the folk on BH is this. Rather than look to save everything you can on professional fees find the right fit for you. You need to work to find the right person for you, they are there and they will save you money in the long run. Bear this in mind. A good tradesperson will cost you £250.00 per day at least. Say £1250 a week. A good designer only needs to save you one weeks labour on say an extension and they have washed their face, never mind any material savings.. and here we are splitting hairs on how fast you can draw in CAD or look up the building regs to check something!
Don't get hung up on a few hundred quid on design fees and how fast someone may be on cad.
The test is this. Can my designer deliver what I want and save me more than I'm paying them any extra in fees compared with just getting a bog standard "off the internet" design.