‘Best on price, best on quality’ is one I think I heard, unless I just made it up. Two ‘bests’ can’t be bad, repetition for reinforcement is common in ads in English at least. ‘The best products at prices that suit your pocket’ is another one I think I heard in an ad. If it’s an individual product then ‘best in class’ is common, i.e the best in comparison to similar products within a certain price range. It sounds ‘classy’, without mentioning budget prices.