Also those people that buy say 100 dollars worth of it, are they still called investors or not because that amount is very tiny. I guess speculator is more the term for people who buy btc but probably less than say 1000 dollars?
Those terms have nothing to do with the amount:
An investor is a person that allocates capital with the expectation of a future financial return.
A speculator is a person who trades derivatives, commodities, bonds, equities or currencies with a higher than average risk in return for a higher-than-average profit potential.
And buying 10$ worth of bitcoin is not called investing, it's called being stupid.
You will buy less than the transaction fee to withdraw or to ever move your funds so it could be called wasting rather than investing.
As for the average, nobody will ever be able to tell.
And, it's kind of pointless.