Identical principal repayments are made in both cases to arrive at the ~€2k differential in the cost to the borrower of €300k over the 5-year term.Again you are correct in that instance but the difference is smaller (~€1k) when principal write down is included
I don't know of any lender that doesn't allow borrowers to fix a proportion of their mortgage, while keeping the balance on a variable rate.
The bottom line remains the same - Avant are significantly cheaper than all other lenders for borrowers with an LTV of less than 60%.