After building every (currently 90, wow!) port for static and dynamic, the combined size of installed, packages, and buildtrees is over 30GB. 23GB of this is because of the buildtrees, which are mostly intermediate files (but also sources).

We should keep sources around for optimal debugging, but we can easily shave off >70% by removing the intermediate directories (typically <triplet>-rel and <triplet>-dbg).