---Apart from the obvious, what do you think is a reasonable number of coins to have? (The obvious being zero from all those who are not into it!) I am not just thinking of Rimbit here but any coin - what is too many and what is too few?
for any coin that you want to have you have to invest in it, either your time or electricity for mining or the common way of simply buying it with bitcoin/fiat.
so with that in mind, i think your question is answered.
it is all about what you are looking to achieve with having that coin and for that achievement how much are you willing to risk?
is it profit? then invest as much as you can afford to lose.
or is it as BitWhale suggest like tipping Doge? then buy as many as you want to tip on different platforms.