That's something I never thought of and it would work for me. I get max price for my place without a commitment to sell and know what I have in my pocket as I shop. It sounds legal but the ethics suck.I saw another interesting mess caused by the crazy market. A rural house was listed in January 2021 for 849K. Sold conditional (I don't know for how much). The interesting thing I hadn't seen before was the condition was the seller had to find a suitable house to buy (backwards from the normal situation where you are waiting for the buyers house to sell). Seller got outbid on a few houses and terminated the deal at the end of February. Relisted for 899K this week. wtf. So the buyer was tied up thinking they had a house for over a month while the market continued to reach for the sky and then got their deposit back and told good luck. I have no idea if the seller has found another house or whether they will play the same game again and keep someone on the hook while they search.
It has a drawback. If my house went up in value I couldn't reap the gain unless I jerked the buyer around. If I got more for my place it changes my shopping list. It's wanting to have your cake and eat it too.