But if you have access to machines, then so do your competitors. You won't be generating 50x more profit, perhaps you'll be generating a few percent higher until the market reaches equilibrium and then the owner will make the same as or slightly higher than what he was before depending on how quickly he adapted. The end benefit is the economy as a whole because garments now will cost a whole lot less. Whichever competitor stitches by hand will go out of business within a year so the baseline to make even a cent of profit is with the machine.
Also, the owner took a huge risk and big loans purchasing the machine. If something goes wrong, he's on the hook for it. If the next year, the country decides to implement NAFTA, then the machine is worthless because it can be made in Mexico far cheaper than in his own town, forcing owner to go out of business and eat the costs. Meanwhile, the worker who gets laid off loses no money in his transition to a new job. The economy, however, benifits again because garments are even cheaper than before.
Also, the owner took a huge risk and big loans purchasing the machine. If something goes wrong, he's on the hook for it. If the next year, the country decides to implement NAFTA, then the machine is worthless because it can be made in Mexico far cheaper than in his own town, forcing owner to go out of business and eat the costs. Meanwhile, the worker who gets laid off loses no money in his transition to a new job. The economy, however, benifits again because garments are even cheaper than before.