Well, you can (and should!) set up your DMARC preferences through your DNS records and enable a mailbox to receive those reports, which you can then use to verify if you have any/some problems with particular providers. This is totally free and standard.
But the score I am speaking of was something different: it was the reputation assigned by Microsoft (i.e., something internal) to the IPs from which we sent e-mails. This score was used to determine how many e-mails sent from those IPs would pass/fail MSFT's filters. And to have access to the score and improve it, we had to pay a 3rd. party :).