This is a rare collector's item. Any Chinese export porcelain candlestick would of course be considered rare but still, of those I have seen so far all 19th century candlesticks have been of later date and only entirely molded in one piece.
To make the candlestick base separate and specifically intended for to hold a cast bronze inset candle holder, is instead a mid to late 18th century practice, actually pointing to a date before the typical Rose Medallion decoration was really established.
The decoration of the separately cast bronze candle holder is of a neo-classical wine leaf design really indicating a date around 1800-20 if this fashion indication holds true.
The light blue and red cash or "brocade" pattern which fills the three areas outside the alternating panels between the ridges, also seems to indicate an early 19th century date.
Since the Rose Medallion decoration is not likely to have appeared before the beginning of the 19th century I would like to date this piece to "early 19th century" or, trying for a more precise date, to the 1820's.