Hi. Great question, and thank you for starting the discussion.
I have owned my own tandem rig since 1987. However, it is currently sitting on a shelf, having not jumped it since 2007.
Back in the day, because I could afford the purchase price and maintenance, it made sense to own.
However, today I can see no viable reason to own one, especially here in the US, especially on the coasts, and especially if one is borrowing the money to buy and thinking of it as a business.
Even the small Cessna DZ's I travel to have rigs on the shelf.
But, I keep thinking that I will luck out and find a DZ that wants to rent my rig (like I did from 2000 - 2007).
I charge a $50 per jump rig rental.
JC JC Coldren
USPA I/E (SL, IAD, Tan, AFF)
FAA Sr. Rigger