Holy Moly! Wow, that's pricey. Thanks for the link @FrostRanger . Maybe if I'm good, Santa will bring me one for Christmas.It's expensive, but here's one
https://www.amazon.com/Permafarm-12L-3-2Gal-Food-Grade-Bottom-Fill/dp/B0D9PCLZ14

We've also tried to train them to the nipple waterers. After a week of that frustration I gave up. I followed the instructions in videos and put their beaks to it to release water, removed all other options, etc. They never caught on it. It's too hot here not to ensure they have sufficient water so open troughs work better for us.