Why in the world would the seller pay any sales tax? Not that there would be any, when the seller is not a business.

Here in Wisconsin, sales tax is charged on the purchase of any car, new or used, when the new owner registers it.

It is paid by the buyer.

Just like any sales tax on anything is normally paid by the buyer.

If we buy something from out of state and the seller does not collect it from the buyer, we are supposed to pay the equivalent "use tax" when we file our state returns.

eBay will collect the tax for your in-state buyers for you if you are registered as a business.

If you're selling anything but a vehicle (I think) as a private party, no tax is due from buyer or seller. If you do this too much, there may be repercussions, like the state informing you that you are so a business, with penalties from you having to cough up the tax to fines and/or criminal proceedings. Hard to say how much is too much until it happens! If it makes up a significant portion of your income, you may be playing with fire.

As a big time sniper on eBay years ago when I was collecting electronic handheld games a lot, I'm embarrassed I didn't think to snipe this contest! Congrats!

(I'd have had a six hour cutoff or something if it were my contest, but it's water under the bridge!)