So much conditions..
In contract, price can be fetched only from info record.
In info record, you can only use different price if the validity period is different.
So as per your business requirement, the solution can be achieve by development.
By using an user exit or badi, you can use different price as per your requirement.
You should have to maintain the price and all conditions in a Z table.
System will pick the price from Z table as per your entered data in contract.
Consult with your abap team, they will help you to achieve this.