I had a Futrex for the last 20 years, and it is now at a point in its life where I need to get it repaired or replaced. If I can get it repaired for a reasonable price, I will do this but I will not invest in a new machine.
I am finding that accurate body composition data is not all that important for the type of clients I train. Having said that, if you deal with athletes, it may be a worthwhile investment.
I have had access to various analyzing equipment over the years. There was a mobile program that came around to facilities when I lived near Boulder, CO. Interest seemed so so. I would definitely try to get feed back from Adina above on what she charges and how her cost to profit margin is doing. I would be interested as well and will follow your question. The margin would have to be considerable to lay out $5000 on something with limited daily use.