1. They usually demand higher pay than employees 20-30 years younger with comparable skills.
2. People in this age bracket drive up their medical insurance costs.
Both of these can be easily addressed in many cases. I have clamored for years to have medical insurance separated completely from employment. This will eliminate the employer's cost differential in Item #2 among different age groups. Item #1 can be addressed when people over the age of 50 can demonstrate value in terms of experience and wisdom (and often work ethic, too) that younger people don't have.
I don't see this changing - so it's important that we teach young people that their "big company years" are an apprenticeship. They should strive to be running their own businesses by their late 30's. I expect within ten years, the Fortune 500 will be virtually devoid of age 40+ workers outside of certain senior management roles.
Only if you find out what they made at their current job. People don't just work for salary there are many other factors. But HR pinheads don't know that.
Money is not the only thing people look for in a job. Some people just want benefits, like PTO or they just want to be busy. Some people want to forgo the hour commute to work, and just want a job closer to home. Older workers may not need as much money because the kids are leaving the nest, and they’re getting close to paying off those big debts, like mortgages. They are willing to accept the trade offs of lower pay.