Yes Paula, Melissa is correct. It will depend on your Eloqua package i.e. Basic, Standard or Enterprise. The Pricing page on Eloqua.com doesn't give you the number of Lead Scoring Models, but I believe it's something like Basic = 1, Standard = 5 and Enterprise = unlimited - I think.
You will need to contact your Oracle rep for more details. If you have the basic package, you can purchase additional Lead Scoring models - but if you need more than 3 it can be more worthwhile upgrading to the Standard package and then you get so much more than just lead scoring.