Piggy Bank was added in Update 4.2 and when it was first added you would be able to accumulate up to 120 for $2.99 USD(Varies on the Country) but after Update 4.3 the price and Gems limit will change upon purchase from 90 ($2.99USD) to 1,000 ($69.99USD)
How Does It Work
You can buy it at any time(but the best time is once the Bank says its full to maximize the Gems purchased) and once you purchase it, it will reset for you to refill again and it can be done an endless amount of times but be warned after Update 4.3, after a purchase it will change the price and Gem Cap(how many times is unknown).
How Do I Fill It Up?
There is 2 ways that you can fill up the Bank:
- Player Level Up: Every time you level up you can get 10-25 added to the bank(depends on the level but maxes out at 25 per level) and if the Bank is full, instead of getting the usual 10-25 it will say that its full and it won't give you any until you buy the Bank and empty it.
- Making Purchases with Gems : For any purchase you make in the game with Gems (Be it Opening land with Gems, Skip Timers, Buy Gems costing Characters/Shops/Decor) will add gems to the bank with a conversion rate for every 10 spent will equal to 1 getting added to the Bank(So for example, to fill up the Bank to 90 , it will cost you 900 of pure Gem Purchases).