Board Thread:Tapped Out Help/@comment-95.144.36.168-20150506181642/@comment-26143371-20150506205127

Personally I would say you should upgrade Monsarno Research to Level 16(that's when the last job is unlocked) and the Herbicide Squirter to Level 15(that's the last time the amount of crafting currency from tapping Bob Clones will increase).

Some more information can be found here, here and here