It has been mentioned several times about the added cost of growing gracillaria and chaeto, which I have found is not true. I started with chaeto and caulerpa in my reef tank fuge and the chaeto quickly outcompeted the caulerpa despite relatively low flow and lighting. I now just have chaeto. I grow gracillaria in my seahorse tank which is very low flow (but high nutrients) and the lighting is a single PC bulb, so also rather low. It grows so fast that I have to pull out handfuls each week, which I have transfered to my reef fuge and it seems to grow well there too (although not as fast as the chaeto, but there was more chaeto to begin with. I don't think the 'added cost' should really be a deciding factor when choosing your macros.
Just my $0.02