No, not really people with little to no knowledge place commissions for Bespoke suits every day, that's why you go to an expert and don't just make the suit yourself. I think its a bit of an Igent myth that you have to know a lot about tailoring to make it work for you and I mean this sincerely. I was talking to my friend michael hill (Drakes) a bit ago, about Prince Charles being a "style icon". I said, well I think he's well put together but nothing all that special and michael replied "well he gets his suits from Anderson and Shepherd and his shirts from Turnbull of course he looks good".
I think there's certainly something to be said about this. If you go to a real high end maker you would have to try very hard to come out looking "bad".
That's not to say that knowledge is a bad thing but I think it's generaly a good idea to defer to the proffessional. There was a time when we trusted our butcher, our baker, our tailor etc and respected their advice. Now we are rather jaded and probably worse for it.