I remember my parents being excited about the opportunity to refinance their mortgage to something in the high teens. And now these days headlines act like the apocalypse is occurring when mortgage rates are in the 6-7 range.
However as 15% interest rates implies an inflation rate far higher than 2.3% that argument breaks. With 7% inflation on a 100k house it's worth 760k after 30 years, more than the 600k in the 300k range.
Of course what that means in terms of big macs you can buy is different.
Not only that but if your salary keeps up with inflation, and you overpay the mortgage, you'll have cleared the 100k/7% inflation mortgage in 10 years but it will take 18 years to clear the 300k mortgage.
Sure, having your wage not decrease in real terms is a different challenge, but if that does happen then you're far better off with the 15% interest rate situation.