I keep hearing that there will only ever be 21 million bitcoins.
I think it's a myth for the 3 following reasons.
1) The 21 million figure could change if developer consensus did, and people downloaded the software
2) The base money supply can be easily inflated with off block systems, IOUs and CFDs for example, but there would be many more instruments to expand the money supply
3) Alt coins could become very similar to BTC, and can be easily created
This is important because if we estimate the long term % of bitcoin in world markets, you need to include these other factors, and it will also impact the price.
1) have you ever tried to get a bunch of people to agree on anything never mind the fact that your valuables are going down in price if you change the supply? More supply means it going down in price.
3) alt coins ARE similar to BTC and are needed too. You already know about Gold, Silver, Platinum, Palladium, Iridium, and Copper. These are all used for money and / or are collected for the value that they hold. Putting all of these together is millions and millions of tons and still the price of gold is going up. You just have to look at the long term perspective.
But you are right, though, about lots of things affecting the price, just last night I was watching an article about the total value of all the money in the world and if 2% of this money was invested into BTC the price should be $700,000 per Bitcoin. Well we all know that it probably won't happen but personally I don't care if its 2% or much less, because it still seems to me that that we have a long way to go before we reach close to this number. If it was 90 times less than that the price would still reach $7000.
I think that the same basic rules apply to investing that they always have.
1)don't put all your eggs in one basket.
2)Figure out what the risk is. This means if its new, it has huge risk. This doesn't mean you don't get into it, it means you could make a lot and it could also be a flop. For me, we are in a computer age. We need to think about transferring money over the internet a lot easier than we have been doing and it needs to cost less to do it. I remember when DOS came out and then Windows. I was just starting to learn about investing at the time. Well it's no surprise now where Windows and Microsoft have gone, but on the other side, who would have known?
3)Have patience. If you want to make a million dollars over night, you will never have anything.