We have been seeing a number of complaints lately about incorrect percentages being used for the new Ebay collected sales/use tax. Just in case this comes up as you buy or with one of your buyers FYI.
An Ebay rep explained last week that to ensure accurate sales tax percentages, buyers need to have a plus 4 in the zip associated with their account. If they only have their 5 character zip code, the system estimates the tax rate. You can find the post in this thread:
https://community.ebay.com/t5/Bidding-Buying/Tax/m-p/30091827#M292677