Cursory review of the internet shows that 52 cents in 1965 corresponds to $5.08 today.
It sounds like McDonald’s prices have gone up adjusted for inflation.
Then again minimum wage increases in many places in America have escalated quite a bit. I’m sure that has impacted pricing.
McDonalds doesn't offer a hamburger meal anymore, but a regular burger, small fries, and a small milkshake comes to $7.87 when purchased ala carte.