This is not investment advice, but _IF_ (and that's a big if) some of these coins (mainly Bitcoin and Ethereum) successfully achieve some of their goals, today's price will be extremely cheap. If not, it will probably be expensive. Do your own research and then decide whether you think they can.
There's still a good chance you'll be wrong. Don't gamble what you cannot lose.
I think of money as simply a distribution mechanism for the world's resources - a unit of currency can be thought of like a share; a right to allocate a portion of resources represented by that share. With the dollar, you can be diluted to infinity, with bitcoin, you cannot. With any fiat, it only has value because everyone else says it does. ETH is interesting because it is more than just currency, but it remains to be seen how valuable the ability to run decentralized apps will become.
That's true of bitcoin, but not bitcoin forks. You can just fork the chain and there's your dilution / inflation e.g. Ethereum classic, Bitcoin Cash, both of those are taking value away from the Bitcoin and deflating the currency futher.
In case of the former, nobody knows. In case of the latter... You probably shouldn't do it, unless you want to speculate.