The Hyper 7 is fine as a club racer. There are a couple of upgrades that are worthwhile depending on the model you have (TQ, PBS, PCR or pro).
You really shouldn't need to buy a new buggy for a while. Race a season with the hyper and see how you do. It seems you already realise that just buying a new buggy will not make you insantly faster, so I don't need to explain that to you.