Taxes should have been deducted every year as an itemized deduction ... you cannot also add it to the basis. Inflation means nothing in this situation. And the loan interest had to either be deducted as investment interest on the Sch A OR be capitalized each year in order for you to add it to basis ... so if you didn't notify the IRS each year that is what you are doing you cannot use it now.
https://ttlc.intuit.com/replies/4241480
