not sure if you are still looking
i came across this product and it has really good reviews on amazon as well.
reviews here:
It has a nice combination of hylauronic acid, vitamin C and lots of sea minerals.
60ml for under $22
http://au.iherb.com/white-egret-personal-care-vitamin-c-hyaluronic-acid-2-fl-oz-59-ml/66066?rcode=dtk831
delivery is $5+ or free if you buy over $53.
Vitamin C is the 2nd ingredient which shows that there is a high percentage of vitamin C in the product.
ingredients:
Water (aqua), sodium ascorbyl phosphate (vitamin C), capric/caprylic triglyceride, carthamus tincotrius (safflower) oil, cetyl alcohol, glycerin, stearyl alcohol, concentrace mineral complex blend, xanthan gum, panthenol, allantoin, cetearyl glucoside, glyceryl stearate, glyceryl stearate SE, glyceryl stearate citrate, tocopheryl acetate (vitamin E) sodium hyaluronate, aloe barbadensis leaf extract, retinyl palmitate (vitamin A), potassium sorbate, caramel, phenoxyethanol, ethylhexylglycerin, citrus aurantifolia (lime) oil.
i have not personally tried it myself as i make my own vitamin C serum nowadays.