Ebay will just impose the taxes on your sales.
They will already report your payments to the IRS if you get over $10,000 in a year. And no, that doesn’t tell the IRS how much of that $10,000 was net sales, only the gross (including postage and handling cost expenses)
So does EBay act as the seller; is EBay then going to administer sales tax for their members? I don’t know how EBay is structured or the legal relationship between EBay “corporate” and all the individual sellers on EBay.