How to calculate/predict VM costs

Hello,

i'm new to VSPP and i'm trying to understand how to calculate the costs of a VM (for us and for billing to customers).

I'm evaluate to subscribe to "VMware vCloud Service Provider Bundle – Premier-X Edition" and in product usage guide i find:

"..10 points per 1 GB Reserved RAM (based on average monthly usage) (GB = 1024 MB)

What does it mean "based on average monthly usage" ? If i have a VM that run continuously and i reserve to it 1 GB but it has for example 4 GB assigned, what will be the cost at the end of the month ? 10 Points ?

Does exist a method that permit to exactly calculate the cost of a VM with specified resources (pre-assigned and not pay-per-use) ?

Thanks, kind regards,

Nicola