Ok, so I have a SAAS website where users pay a daily fee to use my platform as there fundraiser landing page.

A new client comes, asks for a discount, and got a 50% off because his brother was a previous client.

Him: Can you please add a list of the days of the year so a donor can donate a day?

Me: Sure, sounds like a good idea, and will probably take me about a week to implement with testing etc. And so I want $$ (hourly rate * one week) for the work.

Him: Don't bluff me I understand a bit in programming, it shouldn't take you more than an hour, and I am paying you, so you should do it for free.

Me: Ok, here is a fair deal, since you understand in programming, build it for me, I give you two weeks and I will pay you double what I am asking for.

Him: I don't understand enough to do it myself, I just estimated how much work it is.

Me: Forget about it, if you want me to build you this feature, you pay. If not you can go to my competition happily.

Who needs bad clients at all?
Why do they think they know everything?
And why don't they understand that time is money?