The Smurfberry Bush works as an In-App Purchase and costs 4,99 USD (or the equivalent in other currencies, for example 3,99 EUR). The Smurfberry Bush will then grow 5 Smurfberries every 24 hours for a total of 15 days. That means the bush will give a total of 75 Smurfberries. After that it will remain in the village but only as a decorative item. It will not give more Smurfberries.
For the same amount of money a “Bucket of Smurfberries” can be purchased. This only contains 50 Smurfberries, so the Smurfberry Bush gives 25% more Smurfberries for everyone willing to wait the 15 days to receive the total amount of Smurfberries.
Please note, after 15 days the smurfberreis bush will not give more fruits, it remains a purely decoration item.