If so, it depends on whether his product has been patented, and whether your patent is an invention patent or a utility model patent. If it is a utility model patent, you should go to China National Intellectual Property Administration to make a utility model evaluation report. According to the content of the report, decide whether to sue the other party.
That is, whether your patent will be invalidated by others first.
Secondly, if the case is successful, then go to court. As for the litigation fee, it depends on the subject matter of your product, but our lawyer's fee is 20,000 to 30,000. If we win the case, we will raise it according to your subject matter 10.
If you want to sue, you have to investigate and collect evidence. If you need me, I will help you.