Do some online shopping around and you can find some really good prices compared to what retail is. Sometimes you can also find free shipping but if you do the math often times even with a small amount of shipping it still is cheaper than retail. I find ebay often has the lowest prices but check around for deals. I don't want to say around $10 each and have it be way off (but I don't think that is too far off for small bottles) but also remember say for the Excel you use 1ml daily, which is like 1 drop, so even a small bottle will last a long time. I doubt you'd use much more if any of the fert either.