

For most buildings the math on how many FP they'll make is rather straightforward and accordingly once they start going up sharply in cost they stop being worthwhile to level for the sake of FP - usually stopping somewhere between level 50 and 70. The treasury goods are nice, but you could level one of the other treasury GBs or build Statues of Honor if you wanted to make more of those. The primary motivation for taking your Arc further can be boiled down to a desire to make FP. I'm going try to address when this makes sense for you and how far you should go :) You may however have noticed that some people have taken Arc significantly further than 80.

The reason for this is that the rate at which its contribution bonus increases drops to 0.1%/level, while its cost/level is now going up sharply. Level 80 is the first major stopping point for the Arc.
