I graduated from a state college in Washington in 1975. Tuition my first year was under $450 for the year. By the time I graduated it was up to about $600 for the year. Room and board was under $1,000; and the food was excellent.
Not much worse by the time I got my MBA from Minnestoa State University in 1988: $108 per credit hour or less than $6500. for all the class credits(60) needed to complete the degree. Add $1000 or so for the cost of texts, materials and commuting expenses.