I've seen the beating a lift gets during rough weather, or when there is a ton of boat traffic in the lake, and there's no way I'd even THINK of DIY a boat lift for a nice boat, unless I had extensive fabricating capabilities, ie. it was basically my career and I built airplanes or something, lol. I DIY just about everything too, but no way. Not with a $65k boat sitting out there at its mercy 24/7.
Yeah, they are "simple" in operation and concept, but they have to be designed right, and hold together, and be very reliable to protect your boat in the worst conditions. Not to mention it is lifting and lowering ~4000 lbs, has to do it reliably, and safely, or it could be dangerous as hell. I hate to be the over-protective guy, but just really not something you DIY, unless maybe you are lifting a 12-foot skiff with a 9.9 HP Johnson on the back, lol.
And yep, most marinas would never allow it anyway. That said, I have seen numerous stories of guys finding older lifts, refurbing them, etc. like was mentioned earlier, and saving a lot of money. I was more than open for a used lift, but I personally didn't want an old one I had to refurb, and my lift-dealer told me when they DO get a used Hydrohoist in trade, they are gone in 48 hours or less. I just bit the bullet, bought a new one, so I get the warranty, latest technology, no hassle, etc. It will basically last my lifetime if I take care of it, so I just consider it an investment for years of convenience.
My new boat is still on order, but I had my Hydrohoist 6600 re-configured today, for back-in operation. It's setup so the back of the boat will be 8-12" from the rear of the dock, so I can step right on or off the swim platform to the dock.
Yeah, will be more effort to back the boat in, but I learned in my demo that backing the Chaparral is total cake, much easier than the stern drive I traded. I'm pretty sure with practice I'll be able to pull into the marina, pivot the boat, and back in. At least that's the plan, lol.
Just made a video today testing it (no boat on it.)