Have you tried just pressing enter at the password screen?
For info - You don't have to pay to change a MS pass
"Reset your Microsoft account password you use to sign in to your computer On the sign-in screen, type your Microsoft account name if it's not already displayed. If there are multiple accounts on the computer, choose the one you want to reset. Below the password text box, select I forgot my password. Follow the steps to reset your password."
Your best bet now may be to boot from a linux USB or remove the HDD and place in acaddy and connect to another machine to access / copy the data on the hard drive