Kjf. Anyone can do the course. There's a good cross section on this one with some real experts, amongst the attendees, and some relative novices out to increase their knowledge. I don't remember how much it costs as I paid it a while ago, but in the mid three hundred quid range. Look at the BDS website and I'm sure you'll find it. I think I'll have answered most of your questions, with some other bits of advice from people who have been on other courses. Every day, in life, not just here, truly is a school day.
The bottom line is, don't be frightened to get onto as many courses as you can. We never stop learning.
Good hunting.