Unfortunately, no. At present time, this functionality is not available.
If the item being listed on eBay is on sale in your 3dcart store at posting time, then it is listed on eBay with the sale price. If the item is updated on your 3dcart store with regular price, the item listed on eBay will still have the Sale price. Price changes would need to be made manually on the eBay side.
The above usually only applies if you are using the “Same Price” option found in the eBay listing template.
Full information on setting up the eBay integration can be found here.