[lsc]

if he was a full-time employee getting paid-for health insurance, an older person costs the employer dramatically more, like 300% more than a young person, for health insurance at least.

Of course, even then you are only talking a grand or two pre-tax, which isn't the world, when it comes to programmer sallary, unless the old person has a bunch of dependents and the employer is paying for dependents.

I think it's pretty common for the employer to pick up most or all of the bill for the employee, and then have the employee contribute for their dependents, but it varies from company to company.