The workers would be at minimum a master in their trade: Machinists, Mold maker/Designers, 3D artists (sculptors), CAD designers, thus the quip of union workers. People of this ilk would make it a requirement to have benefits. Yes, there are empty warehouses in the US. Depending on the state you are in the costs to run a business vary, especially in the area of taxation. You still require a million to start the business. Buying the building (long-term investment) or renting (short term), buying the machining equipment. Note I am looking at this from a plastic modeling type venture where the molds are metal. Then there is the need to have a working infrastructure for sales& marketing, the R&D section, management, shipping & packaging, raw materials, networked computer systems with CAD modules to design the mold, Historians, and then a transportation fleet for materials. Not to mention the holding facilities for the materials, by products, waste, and finished product storage. In essence, there is a huge startup cost for a medium business set for growth. An hourly wage and salary wages would be normal, hourly for the workers and salary for management. This would not be the sort of job where minimum wage would be advisable. Rates range from the mid to high teens plus benefits for hourly, with up to six figures for management salaries. Remember we must also comply with OSHA and hazard rules and guidelines. Waste disposal and permits would be a pretty penny.
In reality, it would not be beneficial to start a company in the US with many other manufacturors already meeting the supply and demand of the current customer base.