jonnythan - your are correct about B/P versus a Ranger, and the cost of a high end BC. But there are some special setup and balance issues one has to understand and take the time to do with a B/P, and not everyone has the interest or the technical skills to do that.
I suspect that most of the BC crowd just add or subtract weight when needed, and some likely just over weight themselves and fill the jacket
I would agree, that if you need all of the features of a Ranger, then you most likely are B/P material. But is everyone in that group? Uncle Ricky had it right when he said there is a place for each.
If you look at the reason for why people buy high end equipment, it comes down to:
1. They actually need the features (really small group - but real)
2. They can afford the most expensive and expensive is better, right?
3. They are technical geeks and just like it for the technical aspects (OK, I can get into that one)
4. Somehow, it makes them feel better, somehow bigger and smarter because they own stuff (ever hear of "limited addition")
I've been guilty of all of the above at one time or another.
Most people would do just fine with a good, well made, good fitting, well taken care of $250 BC. (OK, it has to be on sale for that price).
When someone asks "what should I get", the answer should be what is best for them, not you, not me.
One last, somewhat different point of view - spend 6 years dealing with SCUBA accidents up close and personal. The new guy, with $5,000 worth of equipment is a whole bunch more dangerous (to himself and others) than the someone taking the time to grow in the sport. I would rather have 100 divers on a budget, worrying about their equipment, than 5 divers who think having the best equipment makes them supermen.