Then say goodbye to all consumer protection regulations, safety standards, environmental rules, etc.

You can still regulate domestic vendors to prevent them from reselling products without disclosing they are noncompliant with safety standards or environmental rules (which you personally would face liability for the pollution caused by your usage of a noncompliant product) or other means of having the same effect as current regulations. Currently, we have people dying due to being unable to afford life saving medicine in the US due to its artificially high domestic cost.