They'd cost what the equivalent "made in America" products do today, or a little less due to economies of scale.

For products where nothing like them is made in America, it's harder to predict. It's possible that in America, there would be less workers hired relative to the products made, if technology levels are higher (automation, etc). This could mean that prices wouldn't go up as much as we think they would, but also that we wouldn't get as many new manufacturing jobs as we think we would.

Cheap foreign labor has made basic products a lot more affordable in America, but ultimately I think it leads to a loss of dignity for both American workers (stuck in shitty service jobs that produce nothing) and foreign workers (making cheap crap for foreigners at starvation wages with no health/safety standards).