I would like to agree with you that it isn't sustainable, but previous generations have said the same and been wrong:
https://educationdata.org/average-cost-of-college-by-year#1950
I don't mind if my kid goes to a trade school. I want her to do something that she is good at, that she enjoys, and that makes enough to keep her secure. If trade school does that for her, cool. But currently the rate of women in trade schools is low. Like 2% low. I don't anticipate that changing, but if it does I think every plan I've looked at covers that as an eligible expense.
If trade school does prove to be increasingly popular, I see 0 reason to expect that tuition won't increase in line with what we've seen happen with college tuition.
So if I wanted to calculate increase in costs over a 50 year period and apply it to my problem (costs in roughly 18 years), I'm assuming it looks like this:
1. Determine today's cost (say $100 for a widget.)
2. Determine cost 50 years ago ($10 for a widget.)
3. Determine difference (100-10=90)
4. Determine percentage increase (900%)
5. Multiply times 1/N where N is number of years between number 1 and 2 (900(1/N=18)
6. Perform simple interest calculation using that number over a period of 18 years
If I understand correctly, that would mean that if a widget costing $100 today cost $10 50 years ago, then it would be correct to assume that in 18 years it would cost $424?
If so, then calculating tuition cost in 18 years using that method looks like:
1973 annual tuition cost = $1,600
2023 annual tuition cost = $11,520
Percentage increase = 620%
Average yearly increase = 12.4%
2041 annual tuition cost = $37,232.64
I may be 200% bass-ackwards on this. Been a long time since I sat through a math class.