It really depends on what he's trying to insure. Is he still working and does your Mom rely on his income to survive? Is there still a mortgage that they are paying? Is there a grown child who will need care if he's gone? If the answer to these questions is no, then he really doesn't need insurance at all.
Ideally, if your parents have retirement savings that they are planning on living off of and they have social security from working, then the only extra money they will need is to pay funeral expenses when he dies. This can be handled by taking the money he would use for insurance and instead use it to choose and pre-pay (or save) for burial expenses now.
In most cases, a man his age will be paying through the nose for life insurance of any type, since statistically, it's a bet he's sure to win in the not too distant future. This price will increase dramatically if he smokes, takes any meds and/or is overweight.
In our case, we have 2 small kids and a HUGE term policy because we need both our salaries to survive and we are only halfway through a mortgage and still have 8 years of college tuition to look forward to. BUT, ours is a term policy, we are both healthy and (relatively) young, and it will cease to exist when our littlest graduates college (20 year term). After that, it's every man for himself.

I don't see life insurance as a potential windfall for my kids. And by then, our house will be paid off and our living expenses should be less. Plus we have significant savings for retirement.
So long answer short, it really depends on what he needs to "fund" once he dies. My final advice is this - go term only, not whole life or universal. These tend to be very expensive "investments" that don't perform well and don't provide much insurance for the cost. He can go online and get quotes for the size of policy he's looking at from several agencies, just google life insurance and you'll get plenty of hits. There are also calculators online to help you figure out how much you'll need based on the income you wish to generate with it after the fact.
Hope this helps.