HOW TO GAIN 2500 COINS HOURLY...
As you are collecting from assets, you cannot receive most items which your inventory has 99 of... You receive coins in their place.
A Strawberry costs 60 coins. If harvested when 99 are already in your inventory, you receive 185 coins instead: a 125-coin profit!
Since Strawberries take 1 hour to grow, and you gain 20 energy units in 1 hour, it is best to grow 20 at once (or 40 over 2 hours).
This yields: 2500 coins in 1 hour, or 40000 coins over 16 hours! (To compare... five level-5 Farmhouses yield 1960 coins hourly.)
THIS IS THE FASTEST WAY IN THE GAME TO GAIN COINS.