Hmm, that is a nice setup. With the reinvig from the boots and the rainbow armor, you can get away with researching Summon Earthpower until later.
Also, the Boots of the messenger are only 5 gems in the vanilla game. Not sure about CBM but I think it's the same. The Rainbow Armor is only Con 4, probably making it the best armor at that level, unless maybe you really need the +5 MR from the Armor of Souls.
By the way, if you can have an awake Cyclops who can make a few Dwarven Hammers for you in addition to expanding, you can get the equipment even cheaper.
I think his theory was simply that you can time the research and gem income to coincide with a sleeping pretender, and thus sacrifice little to gain those 150 points. Plus, it's highly unlikely you could afford "a few" dwarven hammers, and the introductory SC gearset, by turn 12.