To drop a flush ceiling on a Rondo furring channel system shouldn't cost you much more than $80 per sqm at the outside finished, depending on what drop and what anchors(under concrete) you may need, materials for the suspension system shouldn't be more than $15 per sqm, add $45 per sqm for the Gyprock and labor tops.o drop a flush ceiling on a Rondo furring channel system shouldn't cost you much more than $80 per sqm at the outside finished, depending on what drop and what anchors(under concrete) you may need, materials for the suspension system shouldn't be more than $15 per sqm, add $45 per sqm for the Gyprock and labor tops.