Numbers under lid rim and on bottom of Yongzheng Vase

by Ethel Allman
(New Paltz, NY, USA)

I have a large, 14" tall, Chinese Vase with the Yongzheng (1723-1735 ) marks in double red circle. On the bottom is also the number 2 6 one slightly to the right and below the other. Under the rim of the lid looks like either a chinese letter and an 8 or an 18. The same vase was listed by someone on Ebay for 59,000, now after I contacted him/her it is listed at $1999. I want to try and date this vase properly. Can you give me any helpful information or guidance.
Thank you. Ethel Allman