No! Within the same series, you can assume that artworks of the same rarities (Common, Uncommon, Rare, Very Rare, Extremely Rare) have equal print counts. Across different series, artworks will often have very different print counts. Be sure to look at the detail page of an artwork to see how many prints of it exist, and read the details when trading.
Some artworks have thousands of prints, while others have just a few hundred or even just a few dozen. Some artworks have no print limit whosoever. So be careful assuming that all artworks of the same rarity are equally scarce or valuable!
As an example, the following trade shows each trader offering an artwork with the extremely rare rarity. However, these pieces are not equally scarce because one has 200 prints while the other has 1200 prints.