Literally never post anything for free anymore because the free crowd are generally problematic and a nuisance like this. I put a low amount usually under $50 depending on the item (sometimes add OBO) and the people that reach out are way more serious and make arrangements. Can even just make their day and give it to them for free when they come to pick it up. If truly just putting for free I just put it in a box on the side of the road and put "free" and its gone within 24 hours. One could also just put the picture up on marketplace as well and put something along the lines of "out on the curb, first come first serve". I also just stop responding to super annoying ppl wasting my time and end up blocking them. Time and energy are valuable.