CubeCraft Skyblock is a specific type of Skyblock: Rather than playing with each other and trading, it is supposed to be a single player game (or co-op game if you wish). Auction house would destroy the whole point of that, hence is why CubeCraft already decided not to add it.
As well as that, CubeCraft Skyblock is unique from others due to the challenges and unlockable stages and islands. Auction house would totally ruin the progress you can build with the challenges, and therefore ruin the whole concept.
For this reason I voted

, just like anyone else yet so far. Hope you understand!