There are many items with free international shipping, I’m worrying about the safety, if something go wrong, like high tariffis, will the seller own that.
These are almost always FOB (Free On Board), meaning the seller covers all costs up to the package being accepted by the postal service. Any costs arising after that - duty, local sales tax, extra delivery costs - are your problem. You probably need to check on your local stuff, so you need to say where you live and ask specifically about costs there. Sales tax and duty are most often the things involved, and there are usually clear limits about what is free. You also need to know what the seller puts on the label (value of contents, samples etc.), since that is almost always the basis for duty. Opening stuff is just too troublesome for locals, they go mostly by what’s on the label.