ISU Billing- Create price line item based on movein date

Hi Experts ,

I need to create a line item for a cost for the first periodic bill.

The functionality should be -

The cost should be a fixed amount charged based on year in which move in date exists.

for example , if movein  date is 19.12.2013 , then the price should be picked up from the period 01.01.2013-31.12.2013.

and not from the period 2014 even though end of billing period can be in 2014.

That is , there  should not be any proration.Price amount should not be divided .

If for 2013 , price is 10 and for 2014 price is 20 , then in above case line item should have amount 10.

How can I do this ? Which variants should I use ?

Thanks in advance!

Nachiket