I don't know how you arrived at a total cost of $260. The prices I see on the TurboTax web site right now are $170 for TurboTax Live Premier (federal) plus $55 for the state, which makes a total of $225.
In any case, the cost is per tax return. If the two people are married and filing a joint tax return, then the $225 or $260 is the total cost for both people. But if the two people are each filing their own separate tax returns, then they each have to pay that amount.
