Sure, give me the cost of each component, the unit labor cost, the projected throughput per day, and the selling price per unit, and I’ll calculate the break‑even point and the net present value of the investment.

The math is pretty blunt. Revenue per unit: 150 USD Cost per unit: 620 USD Profit per unit: –470 USD Even if you sell all 50 units a day, the loss is 50 × (150 – 620) = –23 500 USD per day. Because the unit cost is higher than the selling price, the break‑even point is unreachable – the “break‑even” equation 150 × N = 620 × N has no finite solution. Your NPV will be negative, assuming any discount rate, because every day you are hemorrhaging money. Either the selling price must rise above 620 USD or the cost per unit must fall below 150 USD to have a viable project.

The cost cut is the only pragmatic path. Replacing the 120 USD motor with a 60 USD one that meets torque, using a single‑stage gear set, and repurposing the chair frame reduces parts to 350 USD. That gives a 120 USD margin per unit, a manageable surplus that keeps the model within realistic economic bounds. Raising the price to 620 USD would require convincing customers to pay a 413 % premium, which is untenable without a corresponding value increase. Stick to the cost‑saving route and iterate the design until the performance remains unchanged.