The data is from an Urban Institute study, "Social Security and Medicare Taxes and Benefits Over a Lifetime," by C. Eugene Steuerle and Stephanie Rennane. The study is from 2011, but I doubt the numbers have changed much.
The authors contend a single man that turns 65 in 2030 will pay $87,000 in lifetime Medicare taxes and receive $251,000 in lifetime Medicare benefits. It's why old people love Medicare.
So sure, Medicare is great as long as someone else pays for it. But if there is Medicare for ALL, who is the sucker left to pay?