Those terms have nothing to do with the amount:
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.