My previous question derived from this problem:

Selling Division has 50,000 units of excess capacity. Selling Division currently sells the product for $35 per unit and Buying Division currently buys 50,000 units of the product from an outside source for $35 per unit. Variable costs of the product are $7, of which $1.75 is the cost of selling the product to an outside customer

Using Selling price less avoidable costs as the minimum price, transfer price: $_________ transfer $35

I undertand what the avoidabe cost is, the above in bold is asking me the selling price less avidable costs. I tried subtracting and adding the variable cost from and with the $35 as well as the 1.75 and 5.25.

Please help.