I use the Caddie Buddy one [1], which is a bit more robust for bigger cameras. There are other options where you can use your phone or something, but I prefer using a mirrorless and a good sized monitor.
Oh my! A teleprompter for less than $200! I haven't kept up with this market, but that's so amazingly affordable. I've long switched to tablet for the text, but this is easily 5x cheaper than what I still use from a purchase back when dinosaurs roamed the earth. I'm guessing that mine is 5x heavier too. However, it is one of those things that once you have it, you don't need a new one so I've just never looked to see what is cheaper today