For lighter duty, there is maker pipe: https://makerpipe.com/. it's nice because the bulk of the system is electrical conduit, which I think is one of the cheapest type of beam/tube available.
There have been pretty serious PVC conduit shortages for the last year or two. In construction projects I've worked on, they've had to uprate to (much more expensive) fibreglass conduit as PVC was simply not available.
For other cases, sometimes I wouldn't mind paying someone else a good market rate -- drywall work comes to mind -- but the mental overhead of contracting and scheduling is currently high enough that I end up just doing the unpleasant work I'd rather pay someone else to.