In a recent post on users@, Michael Neumann wondered if it was possible to have the pkgsrc tools install binary packages whenever available, building from source only when needed. Going by Joerg Sonnenberger’s reply, yes it is:

DEPENDS_TARGET=bin-install
Set BINPKG_SITES similiar to PKG_PATH first.

BINPKG_SITES should be set to a list of binary package locations, separated by semicolons, as I recall – see the download page on the DragonFly website for a list.