Decided to finally pick up the Civ V DLC, though still overpriced as I don't play the scenarios.
If you're buying the game it's cheaper to buy the near-complete GOTY version. If you have the game and want all the DLC, there's semi-hidden mini bundles that knock a further 15% off in total. Korea+wonders, Denmark+explorer and Cradle. Polynesia, Spain and Babylon don't seem to have bundles.