There is quite a detailed blog about the manufacturing of the new Citadel structures, including their ingredients and BPO costs.
To get an Extra Large Citadel BPO will cost an eye watering 700B ISK. Yes, seven, zero, zero. Even the 6B ISK for a Medium Citadel BPO is a noteworthy investment for smaller groups, and that does not include costs for the structure components, new rigs, fuel bocks, service and structure modules.
I assume some of the costs will be allayed if the POS and Outpost related BPO’s are refunded for ISK.
I had kind of forgotten about the huge impact this change would have on all the industrialists, and just how much content it will add to their games.
The costs however suggest that we won’t be seeing an initial glut of X-Large Citadels being planted around New Eden. Or maybe I will be wrong – I could be underestimating the wealth of Alliances outside of the top tiers.