if i have an option name set to "checkbox"...

senario:
product base price: $100
attrib a: +100
attrib b: +150

If I add only "a" and "b" (not the actual base product), I should be charged the base price twice + 100, +150.

what seems to happen is that the base price is only added ONCE... therefore leaving a lot of discrepancy in pricing.

Can anyone confirm this or suggest an alternate ? I want to allow customers to select multiple options in one go.