We sold many chicks sold over the years. Most customers end up as repeat buyers or give referrals. Some have even grown into close friends. It’s a good sign if someone asks questions because you can get a feel for how much research they did before deciding they want to come over and see chicks.
Usually the lowball offers are via email before a meet so it can be ignored. It’s only a pain if you spent several email exchanges describing the breeding parents, sending additional pics, and my favorite- giving advice on how to raise chickens, buying coop, answering medical questions about one of their hens, etc ..,., then they decide they want to buy my hens (not for sale) instead of straight run chicks.
Yet If somebody offers to buy the entire hatch, I’m always up for a giving a discount. Emptying out the brooder in one sale is worth being done with all the CL questions.