Great game, except for 1 uncool move

There should be an option to change missions, because after playing a lot(really great game) Ive encoutered a mission requairing me to research fruit. Thing is, it can be researched only by 500 gems! It means I cant play anymore, because I dont have that much and this mission is in my best city. Please, change this, because it was really not cool move.

Kodeman010 about Puzzle Craft 2, v1.5.1