I totally agree with the trailer concept. But you also need to pull it. And in case you have not done a lot of construction work, understand that while delivering materials is free, returning excess materials is not an option outside of carrying it back yourself.

Basically I can tell you that yes there are a lot of advantages. Another thing is carrying things like fill or gravel. Good luck with a van on that one. And while delivery is an option it depends on how accessible the area where you want it delivered is.