Not needed but "highly" beneficial if you have room in the budget for it. I wish I had purchased on years ago now that I have experienced how much faster and easier everything is when you're not pinned under a set of jackstands. You can defiantly get by without one though.
I agree with you completely, Henry, that's exacly the way I see it today. But Dave's making a good point for someone who is just starting to collect tools. Or to put it another way, a multi-thousand dollar lift is a good idea depending on what other tools you are foregoing because of it. So it depends somewhat on what the overall tool budget is.
Knowing what I know now, if I were starting over with tool buying
in order to build an SLC as my first project, I might buy a lot of relatively expensive fabrication-oriented stuff before I bought a lift. If a lift kept me from getting a compressor, I wouldn't get the lift. Same for a small sheet-metal brake, a tig welder, good tubing bender, tube flaring tools, good angle grinder, die grinder, set of carbide burs, etc.
IOW one thing that's different here is that the very first project is fabrication and assembly, not a repair, so I suspect for a long time he is not going to need to get
under anything. So I'm wondering if the right advice is: "don't buy a lift until you get sick of not having one." The per-dollar benefit of a lot of those somewhat-expensive fab tools can be a lot higher than that of a lift because they so directly affect the quality of the resulting car.
I think the idea of visualizing the assembly sequence to see exactly where in it you need to crawl under the car repeatedly is a really good idea, and a careful read of a good assembly manual should accomplish that. That point might be pretty far down the road.