Depends on what you're doing. Me, I work with just flush trim bits, and just pop my router plate out of the table. Works great for what I do, I have no need, or desire, for a lift. However, if I ever decided to go to precise depth routing as some of those here do, I am sure I could figure out a simple homemade solution; which would work out fine on a once-in-awhile basis; but, doing that on a regular basis, I imagine I would change my mind fairly quickly about wanting a router lift. After that, if I couldn't figure out how to make my own, I'd decide which of the ready made models would make me happiest. Simple.
And I just thought of how to make a simple gauge, for once-in-awhile precision depth routing. Two U shaped pieces of plywood, with a machinist scale between them, held in position by the two pieces of plywood bolted together. Should be accurate, just a bit of a pain if you wanted to use it often. This likely is not a new idea, but I don't recall seeing it before. Should be able to find a machinist scale for less then $1. Or, if you wanted, you could make several, of different depths using different length legs on the U.
I am not cheap. I am broke.
"It ain't what you're told, it's what you know." - Granny Weatherwax
Some days, the supply of available curse words is insufficient to meet my demands.
Call me a craftsman, artisan, or artistic, and I will accept that. Call me an artist and you will likely get a quite rude comment in return. I am not a @#$%ing artist.