Just buy NIB classics from the auction site. Try here in the forum. Better yet, go to that electric site where they don't know what to do with a balsa kit and they dump it for $20!
There is more balsa hidden away in closets than a man can count, good old fashioned balsa, dense, light, even grain, generous amounts of spruce, hardware, etc. When I build them, I toast the guy that bought it, for choosing a wonderful kit he left behind in his estate. Pica, SiG, Midwest, even Tower are among my favorites. The boxes are yellow, sometimes the plans have a water stain. That is the charm for me. I picked up an old pattern plane kit that had 5 shipping labels layered on the top of the box. It all stops here, and finally sees the building board.