You will face consequences depending on what you decide to sell them.
Attract guilds, befriend notable figures (or feud with them), gain riches and influence - and one day, you may even decide the fate of the whole town. Go ahead! Change bottle shape, label type, icon, and colors. Was it easy to learn? You can buy them from traveling merchants: it can be pricey, but successful haggling may save you some coin. Add the base: water, oil, or… something else.