This exactly what I had been doing ever since I had started doing bitcoin. I keep on buying bitcoins even if it is just a small amount whenever I have some extra cash on me regardless if the current price. I see bitcoin as a great investment so I'm looking forward to be successful in the long run.
Same boat for me. Buy with extra cash so you don't feel it in your day to day and just wait. You'll feel worse if you chose to ignore it rather than investing and having it flop.
Bitcoin supply will only be 21 million Bitcoin worldwide. Bitcoin's declining system of creation every four years resembles an economic system based on deflation and with the increasing supply of bitcoin, bitcoin prices tend to rise. Thats why people will also buy this coin.