This doesn't work. The company will be valued primarily on the final year's revenue. To be a "good deal", the total amount of revenue over 3 years must be <= 8

This doesn't work. The company will be valued primarily on the final year's revenue. To be a "good deal", the total amount of revenue over 3 years must be <= 8% of the valuation. Since companies are normally valued at 3-5x revenue, that means that the final year's revenue represents 20%-33% of the valuation. No one will ever pay 20% of the value of the company to own 8%.