$30 retail, can probably get them around $26, it's not bad except for the support units. Maybe the support units come with lots of extra stuff? Alternate flags, that sort of thing? Fingers crossed.
I imagine the core is priced the way it is to suck people in, bit of a loss leader to drum up future sales. Definitely makes sense to buy two cores now. Especially if new infantry packs won't be out til September or thereabouts.
Games will get really expensive if you want to go above tournament legal army sizes. Bit unfortunate. A full squad of infantry plus a support unit would run about the same as the cost of what we're guessing will be a full sized tournament legal army. I see no epic siege scenarios in my future.