Are stonemasons all they're cracked up to be?

Definition:

A trained stonemason always quarries the right blocks of marmor with his strong arms. He breaks less and our builders always have the material they need. For every level of expansion this building increases the marble production by 2%.

For further details see:


http://ikariam.wikia.com/wiki/Stonemason


Okay so i threw this question out and this was what the wonder that is flipside came up with, condensed down and reworded into Kaz speak:

The idea: Would it be more efficient to donate to the island resource or to max out the stone mason?

The calculations:

270 workers (without overloading) @ level 12 -- needs 89,127 wood to upgrade.

At level 13: 302 workers (Without overloading, this is nearly 12% improvement) @ level 13 -- needs 106,217 wood for upgrade

So assuming your the only one on the level 12 island that ever donated you actually come out basically the same if you instead donated your wood to the mine rather then maxed out your stone mason (stone mason at levle 16 gives an additional 12% marble vs a level 10 stone mason).

If we worked en mass following the above principle we'd be much better off donating the wood vs. investing it in our own Stone Mason building. Granted that you could still level up your mason as needed.

Conclusion:

If you level off the Stone Mason at level 10 and just donate what would have been put into building it to level 16 into the islands mine you get the same result and save 48,640 marble.

If you had maxed out your Stone mason it would take (assuming you're overloading your resources to the maximum and on a level 13 island) 59.78 days before you broke even and made the 48,640 marble back from the benefit of your additional 12% production.

Overall:

It would be a good idea to eventually max out the mason but for the time being until it's necessary a level 10-13 mason is sufficient.

How clever was flip?