I went to the Vatican Museums in March 2023, so it was before the recent change in hours, etc. However, I'd be really surprised if they don't still have a line for people who need to buy tickets. That line used to move very slowly, but they did admit some people from that line to the building from time to time. The museums now open at 8 AM rather than 9 AM. I don't know what that means about how early you should get over there if you hope not to be in line for 2 hours (random number I pulled out of the air).
There used to be (sometimes) someone from a tour agency hanging around with excess tickets to sell. Those tickets were probably marked up, but they were a lot less expensive than taking a tour. If the tickets are now tied to a specific person's name (not sure about that), I don't know whether it would be possible to buy an aftermarket ticket that way. And needing 6 tickets would make it very tough, I imagine.
You might take a look at Get Your Guide to see whether it has cheaper tour offerings that would get you into the building. If I wanted a full-fledged tour, that's not the way I'd go, but it might be a cheaper option for folks who really want to do their own thing. The Museums have an audio guide that may help understand what you're seeing, but I stopped using mine when I noticed essentially the same information posted beside the first couple of objects I stopped at. I was happier reading the information than hearing it. Of course, it was easier for me in March; the Museums were crowded in a lot of places but not packed wall-to-wall as they may be in May. You might have trouble getting close enough to the posted information to read it.
The Vatican Museums have very rich collections, but the viewing experience in the major galleries on the way to the Sistine Chapel (and in the Sistine Chapel itself) is pretty much miserable. I think it's worth considering whether it's worth spending (potentially) a lot of time in line for such an experience. It's not as if Rome doesn't have many months' worth of other glories to see.