Yeah cylinders are pricey no doubt... The cylinder in the pics of the canreef photo gallery is well over $50,000.00 so yeah not too cheap!
These ones would be much more affordable though, I would guess that I would charge about $4500.00-$6000.00 depending depending on the options and the stand and canopy for a complete turn key aquarium with sump, pumps, lighting, skimmer, center overflow. For just the bare tank with black acrylic tube overflow, bottom, and top with cutouts and lids I would ask around $2000.00 for a 24" tall cylinder. Not cheap but very very nice!!!