Valid question. I never build them in my games for the reasons you mentioned.

Here is the best breakdown I can give:

Monastery:

Cost: 12 Mats

Build Time: 10 Turns

Required tiles: 4

Upkeep: 30 pop, 2 Gildar

Output: 3 Spell Points ( spell research points)

3 Arcane Labs:

Cost: 9 Mats

Build Time: 15 Turns

Upkeep: 15 Pop, 3 Gildar

Required Tiles: 3

Output: 3 Spell points

While the Monastery cost less gildar to upkeep and takes only 10 turns to build, these are the only advantages over the 3 arcane labs. In fact, this building not only costs more pop and more tiles, but you don't get any of the Spell points until it is finished. While the total amount of spell points received from the Monastery in the same 15 turns is only 15, the 3 arcane labs also net 15- 0 for the first 5 turns, 5 for the next, and 10 for the last 5.

I am not exactly sure how you came to this conclusion.

He's right in a way, your earlier comparison didn't consider that the Monastery-builder can continue building other things in the last 5 turns - he needn't sit idle for 5 turns collecting points while the arcane lab-builder catches up, but can make use of that extra build time. Theoretically if you built 3 Monasteries in a city (is this even possible? not familiar with the building), after 30 turns you'd have 90 points generated and be up to 9/turn, whereas a guy that spent 30 turns building arcane labs would have 75 points so far and 6/turn. I mean.. it's still not a very good building and looks like it could use a balance adjustment, but in a situation where build time is your only limiting factor and tiles/population/materials are not a concern, it can be better than the arcane lab.

Yeah I suspected as much, but still - you could build something in those extra 5 turns, if not another Monastery. Build time is a meaningful resource when you're generating population/materials/etc faster than you can make buildings.

However it being a one-per-city building means that we shouldn't be having this conversation at all - it shouldn't be arguably maybe better than an arcane lab in the right situation, it should be something undeniably useful and perhaps overpowered if it were spammable, else why limit it? A percentage bonus would certainly be one way to accomplish that.

To me buildings like this are just evidence that the economic and city building part of the game just wasn't thought through properly. They are presented as an alternative to spamming arcane labs/studies/workshops, but in fact they are either sub-optimal and therefore not worth building, or they are so good that you have to build them. Being able (almost forced) to spam these kind of buildings is just wrong in so many ways, and that's not considering how this makes even small towns able to take up huge areas of the map. It feels like Brad & co don't get how to make this aspect remotely interesting. Remember when people started complaining that all they were doing was building studies everywhere? SD's solution to this was allowing studies to upgrade into libraries (for free!) that produce twice as much research for the same costs, reasoning that this way you would need to build fewer libraries, but in fact just making the problem worse. Come on! One of the recent patches removes tile limits altogether, and though I didn't like that mechanism, at least it acted as some sort of limiting factor on city expansion.

Considering what they have to work with, I doubt that the dev's will be able to create an even remotely interesting economy in ewom. IMO the best thing would be to start from scratch, so I'm hoping thats what they did for Fallen Enchantress.  

uhg we don't need ranting posts like that please - lets try to keep this constructive.

The simple fact is that higher tech buildings need to be either more efficient - or- have some unique effect or ability that a lower tech building does not have.

We want Elemental to be more than a spreadsheet game so it is better to have a higher tech building with a special ability rather than a percentage boosting ability.

<insert flogging a dead horse icon> i would like to really stress that the devs realize the mistakes they made and put many band-aids on the game to make the engine work. Didn't frogboy just authorize the hiring of more staff ? Yes bring on the people to do the work !!

I'll rant if I feel like ranting, thank you very much. And I was being constructive when I said "start from scratch", as I honestly believe that would be the best thing to do.

I would change every 'arcane' building from producing actual arcane research points to giving a percentage modifier. The 'base' research points would be produced by the sovereign. So for instance a sovereign produces 1 arcane point per turn, but when he's in a town with an arcane lab he gets a 50% bonus, making him produce 1,5 arcane points per turn. This way you actually have to choose between staying at home and doing research, or going adventuring to gather experience points and being able to use the stuff you researched.

Something like this would make a lot more sense lore-wise (only the sovereign can do magic, but everyone in the whole world is able to research magic spells?), and it would add some more strategy to the game.

I agree that different buildings should have unique effects, allowing a free enchantment is a good example, it gives us actual options in construction.

Well, in fact if you read the lore, they don't "research" magic, they find ancient text and research the text. It's more like translating the text and understanding the meaning of it. Because, before the cataclysm, there was technology and magic. It's just lost. For the monastary, I just think that it's a "relic" from the first version of War of magic because back then, you could only put 1 building of each type in a city. So, every building, even not optimal, would count toward adding bonus to your city. With the system change, they should revise this kind of stuff and adjust them. I like the idea of Satrhan, not only with the Sovereing being in the city but something  like if you choose to specialize your city in, let's say, magic, then you wont be able to build something else OR have some unique building related to this. If we take the bonus that the city get when they level up, you could say that you need the city to have x Lvl in magic (or arcane research) to be able to construct monastery. Same thing with Gold, research and we can replace random unit spawn by military. I think it would add some more though on what you want to lvl in your city.