Yes, getting pricey, but, historically speaking, not too bad.
In 1975, Mobil 1 was $4.00 a quart and was only sold at Mobil gas stations. And since someone mentioned sales tax... add another 4% (the sales tax rate back then).
Adjusting for inflation, $4.00 is equivalent to $19.00 today. Yikes! That was mighty expensive back in the day.