The average gift card that you will obtain when performing the steps described in this guide is worth $25. Overall, gift cards value ranges from $5 to $100.
This method can be performed by individuals and small groups of people. You can involve some close friends contact and work together to obtain gift cards.
SMS is the only "investment" for this BUT after performing the method few times you will need to alter your IP, hence a free or paid VPN/Proxy is required.