I can’t tell you what grammatical construct this is; I can tell you the meaning:
The sentence poses a hypothesis. There is a group of people who apparently don't have a lot of money. Hence they cannot pay for the consequences should a particular risk materialize and they buy insurance to safeguard against the economical consequences of that risk occurring.
Now, take another group of people with enough money. They do not need to insure themselves against this risk because they can pay for the consequences out of their own pocket. That is, they think the cost of insurance over X years is more than the cost from the risk materializing itself once every X years.
Now suppose this first group of people, by magic, suddenly has enough money. Then they don't need insurance either.
So, "were these people to have enough money, they would not insure themselves"