I think if you are 21 and have owned it 3 years then you 100% owe yourself some boost. Ive owned my Glanza 5 years and have fallen out of love a few times. The only thing that stops me selling up is I know that I will only find myself regretting it and trying to buy another 1 which will never be the same. Id say sell it and go for a boosted starlet you will never look back.