i agree with what has been said about deciding on whether to buy it or not based on whether you think you'll use it in the future. but you can also consider if you'd play it more if you got a better one. as in you spent more money on something so you're more compelled to use it.
what do you mean by "outgrow"? as in you're not satisfied with the sound because you've become more advanced, or you feel bored with it, or you physically outgrew it..?