Walk away and find the right clients. Some “clients” do not understand or value design work so you need to identify them and walk away.
Some clients will ask for a discount or would want a bargain…if you go down that road neither you or the client will be happy. A) You’ll be pressed to work fast in order to make a profit. B) Usually the clients that want a discount also want the most work done or multiple revisions so they’ll want you to keep doing stuff for free.
There’s also the “I have more projects we would like you to work on so give us a good price”. If I had a nickle someone said or implied that. When somebody says that just offer to give them a discount on the “next” project.
Some people are just cheap and some just don’t understand. It will be hard to get the right compensation from the cheap person and it will be hard to educate the person that doesn’t understand. Just walk away and don’t dwell on it.