Yes, DCA method is the best method to invest in Bitcoin. You asked your friends to invest in bitcoins using the DCA method to accumulate bitcoins which is great. Yes, you are right about DCA method being very effective method for low income people. Those who don't have enough money to invest in Bitcoin, if they can invest in DCA method for long term then their investment amount will be quite big at some point. However, if you have a low income now, you will try to invest according to your means. Never invest more than you can lose. To be successful in investing with the DCA method, you need to continue with DCA for the long term.