It would be natural to assume that ink bottles date to the beginning of glassblowing and the written word, but prior to the 18th century, the most common form of ink was a cake or powder, which the writer would mix with water. It was only in the late 1700s that liquid ink in wide-bottomed was widely available for sale.
Ink bottles differ from in that the bottles were designed to serve a purely utilitarian purpose (i.e., to hold ink). Inkwells, on the other hand, were often more decorative, the sort of thing you’d want people to notice on your desk. Consequently, inkwells were more expensive than ink bottles.