one way heat pipes? finned heat sinks? some sort of captured ammonia system? we're talking half a million/ footing here easy.

Actually, you're talking about a welded steel tube through the concrete pier (could be used as part of the reinforcing steel) which terminates in some sheet-metal fins, which might be steel or might be aluminum.  The tube has maybe a pound or two of anhydrous ammmonia in it (costs about 25¢/lb even at today's ridiculous prices), or you could use propane.  The "one way" effect is achieved by simple physics:  liquid pools at the bottom, while vapor condensing at the top runs down the sides (to make it run both ways you need a wick to get capillary action).  The finned heat sink at the top could be more steel (but requires rustproofing) or an aluminum extrusion (much less money in fabrication but pricier material).

You're talking more like a hundred bucks a footing, or a small multiple thereof.