I use one I bought off eBay after I didn't have time to make one myself. I wasn't going to spend over $150 for these devices. Anything above that is just a waste of money in my opinion.

Found Inland Curl (look on eBay) and was simple and $140.00 with some shipping. I got it and did not work the first time I tried to use it. With curved hull, suction cups could not stick. I contacted the guy. He gave me cell number. We talked and he said he didn't take returns but send it back and he would modify it for my hull. So I did. Within two days it was back in my mailbox.

I tried it out just before Supra reunion and oh my, what a difference it made. Also, it has never come off the side of the boat, not a once while we are surfing. Doesn't budge. It does have the teather cord because it will sink but after hours and hours of surfing, I often forget it is there. My wave isn't perfect but had rave reviews at the Supra reunion. I love it because I have four family members that are goofy footed and it takes all of two minutes to swap sides of boat. No listing, full ballast, tall wake.

So, what's your time worth? Sure I could have spent less on parts but wasted an afternoon (or two) of my life building the same thing.

I believe if not mistaken two other forum members have bought from same place after my referral. Inland Curl may have a Facebook page as well you can look up.
I recommend this guy because he was stand up and apologetic about it not working from the start. He said he would take care of it and indeed he did. He even texted me several times to get follow up results. Couldn't be happier!