Great silk embroidery and I agree with the date of 18th century. The colors are nicely faded a little and the quality is what you expect from this period including a fine stitch. The Dragonfly represents Change but also Instability. It is said it is a popular subject for poets and painters. Asian antiques are sought after and prices are good at the moment.
My estimation is a reflection of the prices made in auctions today for objects with more or less the same quality as yours.