For your family member to pick up buyer clients, you're not going to be replacing zillow or redfin for free. Sorry, ain't gonna happen. And if you try and fail, which you will on a $0 budget, the free website could actually COST your family member business. Instead, I'd try to focus on content that distinguishes your family member from the other 20 real estate agents I can lift a rock up to find. What's he do differently? When he has an introductory conversation with a buyer, who then goes and finds his website on Google that night, what's going to get him to pick up the phone tomorrow to call your family member back? That is the content he needs.

On the listing side, seller clients, I'll admit I have little actual experience, because I generally only work with homebuyers as a lender (if you need to borrow money to sell a house, you probably did something wrong lol). With that in mind, I'd suggest here focusing on listing websites. The website dedicated to selling a particular house. Get a template going that he can drop in pictures and show to perspective sellers during listing presentations. When he's sitting down with perspective sellers, he can whip out the tablet and show them what their home's website will look like when they list with him. I'm pretty sure these custom websites don't really actually sell homes as I've yet to have a client link me to the 123MainStOakland.com website, they link me to redfin.com or zillow, but presumably these 123MainStOakland.com websites get sellers to sign the dotted line with the listing agent, which is where the REAL sale is from the agent's POV, and after that point (the sale was getting the listing agreement signed, actually selling the house is incidental to that) many listing agents couldn't give less of a fuck as evidenced by half of the threads on this forum.