Would recommend looking at a second hand guitar as for $300 you could find a decent guitar that will perform much better than a brand new one of a lesser model/make. Also when you improve this guitar will still be good enough for you whereas a cheaper model won't sound as good and you will likely have to replace it sooner in order to get the performance you require.

Try looking in a few local guitar shops, most of them will have second hand guitars and will give you advice as what is best for you.