A firm uses negotiated transfer prices to transfer costs from the Seller Department and the Buyer Department. Buyer Department uses a key input from Seller Department. Buyer Department can buy this good from the external market for $104 per unit.

Seller Department assigned the following per unit costs to each unit of producing this input.

• Direct materials: $21 per unit
• Direct labor: $25 per unit
• Variable overhead: $21 per unit
• Fixed overhead: $10 per unit

What is the range of negotiation?