Billingham Packaging is considering expanding its production capacity by purchasing a new machine, the XC$-750.$ The cost of the XC$-750$ is $$2\mathrm{.}75$ million. Unfortunately, installing this machine will take several months and will partially disrupt production. The firm has just completed a $$50,000$ feasibility study to analyze the decision to buy the XC$-750,$ resulting in the following estimates:

Billingham could instead purchase the XC$-900,$ which offers even greater capacity. The cost of the XC$-900$ is $$4$ million. The extra capacity would not be useful in the first two years of operation, but would allow for additional sales in years $310.$ What level of additional sales $($above the $$10$ million expected for the XC$-750)$ per year in those years would justify purchasing the larger machine?