I dont know for sure, but I doubt you will get your actual score for free. I could be wrong.
There is no set score that will net you X interest rate or risk level. Also, the tiers that you speak of differ from company to company and arent split into tiers. When I evaluate a credit record (I use Equifax) I consider the debt to income ratio (DTI), number of collections, amount of equity, as well as the score. The score is a good initial indicator though as to whether we will be able to finance the customer or not. Anything below a 600 beacon is challenging.
In other words, there is more to it than simply your score and your score will differ between the three agencies.