Your company plans to buy from suppliers 1 million parts per year for the next 3 years

(starting a year from today) at $5 per part. You are considering producing the parts instead.

The production facility costs $1.2 million today and is fully depreciated over the next 3 years. Production costs will be $4 per part. After 3 years you will be able to sell the facility for $50,000. The cost of capital is 10% and tax rate is 35%. 

Should you invest in the production facility or keep buying the parts?