There is no "I have 3K crown jewels". That's the city's fund. The crown jewels show for everyone, but only the mayor can actually spend them and the crown jewels + upgrades are locked to the city.
as of 2016-09-11: Player level: 44, City: Eolythes, Blueprints: 517, Mastered: 419, Crafted: 78.61K
(except for tier 1 and some tier 2 artifacts mostly running my shop/gearing self sufficient)