It would be nice to also see the cost for funding perks in the details screen of the guild buildings. As it is now I have no idea what the cost is until it needs to be funded. Without this information it is hard to plan on saving for the next funding drive, that is to make a decision on whether to spend for upgrading/training or on saving for the perk funding.
I thought it told you it, apparently it doesn't, and there's no reason it shouldn't! +1 When you're going to upgrade the building, I believe it does show you how much it costs to donate for the next level of it, so at least you can make some decision about that.