My violin is a $250 Toyama (I don't even know what model it is) and I have been using it ever since I needed to change to a full-size violin which was a couple years ago. It does have a bright tone, but I think G is too flat and E is too sharp and thin. In April next year, I will be having my grade 6 exam.

Should I upgrade my violin beforehand or wait until grade 8 exam? And do I actually have the need to upgrade it?