Well that's stupid
#eBay scams
misty narwhal
deft remnant
eBay generally has good buyer protection that generally sides with the buyer. In general, if you get scammed you'll get your money back but it could be a process that takes a month.
That being said, the listing you posted for example, is a auction. The price could increase as others bid on the item. The seller can also pay extra to have a hidden bid minimum on their items -- so you may not win if the price is too low. Secondly, sellers sometimes charge a high amount for shipping then necessary, which isn't included in the bid price.
karmic oriole
This is rather a normal thing. Switch sold as part, not as a whole.
If you are afraid of scam, know that eBay has a very good refund policy, a bit too unfair for seller, actually.
This should be an unhacked Switch as well, so no risk of banned unless the seller said so. If it's banned, then you have all the right to get a refund.
That's not all about being banned, haha
A banned Switch can't get access to the eShop
But this should not be the case, so no worry