The history of Delft Blue goes back to the 17th century. There are apothecary jars made by Delft Blue that are very old and worth quite a bit of money as a recent Christie’s auction proves, however these are not that old. I have found several that match the ones you have in style and artwork, if not in contents. Worthpoint has one that went for $38 and change and there are two available on Ebay going for about $35 as well. Now the confusing part…these are made by a company called Oud Delft (old Delft) that started in 1920 in Nijmegan and is now owned by Detftsche Huys (1995). http://www.delftschehuys.com/index.php?option=com_virtuemart&view=category&virtuemart_category_id=11&Itemid=112
This link will take you to the apothecary jars which you will see are exactly the ones you have. Brand new they are selling for $40-$80 depending on size.
I hope this helps.