Why does it cost $6.99 to open piggy bank?

I can go to the "store" and buy 30 gold bars for $4.99. Why would I buy 30 gold bars for $6.99 just because it comes from my piggy bank? It really seems like a scam. I didn't say anything when somehow I went from being able to collect 100 gold bars in my piggy bank and to all of the sudden it changed only 30. It just sounds to me like they are looking for ways to rip people off. I like place candy crush soda saga, but I think I need to stop giving them my money.