Your personal income and budget cannot be ignored.
Even if I would use a 200L every day, The $5000 price tag would mean I would have to impact my family's finances in a big way. No lens is worth that to me, regardless of its usefulness.
Well, I did say it is a personal decision. For me the lens is worth every penny. It allows me to shoot in environments and situations that I wouldn't be able to with other glass.
Like I said my photography has been supporting my family (full time) for 20+ years and more than pays for any equipment I need. but I'm also very selective about the equipment I buy. I only own 4 lenses but they are lenses I would hate to have to work without. And when you don't try and buy everything you sometimes are surprised at the gear you can afford.
I would hope that someone would have better sense then to drive there family into financial ruin but good camera equipment has always been expensive.