18th or 19th Century Undecorated White Porcelain Reticulated Bowl, probably German

I purchased the bowl from a reputable antiques dealer in southwestern Pennsylvania, from whom I had purchased and consigned many items over a 10 year period, mostly porcelain and pottery. At first I consigned the bowl, but later decided to purchase it. I don't remember how much I paid her for it, but think it was about $125-$150. We had a long standing business relationship and she always gave me a fair price on items for resale. The blue underglaze mark is an arrow with a line through it. I've thought it to be from an early German factory, undecorated to be given to an outside decorator, but never was. Some think the line through the arrow denotes a piece that is imperfect, others think it denotes a piece ready to be sent to a decorator outside the factory. Tiny black dot in bottom of the bowl is a factory flaw. There are no other chips or cracks, not even in the glaze. Bottom of foot is unglazed. An online appraisal a few years ago placed the value around $700.00