Except for a couple of small orders, I have been building with "Hobby Lobby" grade balsa for a couple of years now. When they get in a new shipment, I go through it and grab anything that looks reasonable. Much of it turns out to be 6-8 lb and their recent stock has been pretty good. Fortunately for me, the other scavenger hunters are closer to other stores, so I usually get first pick. Far cry from calling up MAL back in the day but what is - is.
I use 1/16 where I used to use 3/32 and cut out a lot more of non-critical balsa, hollow thinner, replace blocks with molded, etc. My planes are coming out at 60-65 for a full size PA. Not light but not heavy either. The biggest savings however comes where most would question my sanity (some do that anyway). The Finish. For all but a handful of us those extra 4 or 5 points to go from a 14-15 to a 19-20 just aren't worth the weight. I try, not always successfully, to keep the workmanship clean but piling on the clear is just not going to happen anymore. That is just me and I don't prescribe it for anyone else.
Ken