We all look back and think that we should have bought more back in the days, but in the next 5-10 years we will say the same about today's prices. We'll be like; 'do you remember the price around $10,000? I feel so stupid for not having bought more'. Adding to your position today will help you look back happily instead of feeling like you have missed out big time.
In the end, not many people will be able to say that they own 1BTC, which you can. Bitcoin surpassed 1 ounce of Gold in terms of dollar value, and the next target is to surpass the 1KG dollar value of Gold (currently $46,450).
Most of people who invest in any cryptocurrency can hardly imagine waiting for something for 5-10 years from now, let's face it, life is so accelerated that people only look how to get instant rich. But even if you give them opportunity for that, what most of them do is to mess up - 2015 price of 1
BTC was even below $200, two years later $20 000 and how many of us get rich after that?
10 years of Bitcoin is not enough to convince people that this is something unique, and that Bitcoin is preeminent over gold, silver, fiat, stocks... So act now or be sorry in future.
For OP, you should wait 18 million Bitcoins to be mined - but there is not too much differences in what's left - 3,2 or 3 million for next 10 years is compared to 18 millions mined in first 10 years exactly 6 times less coins.