I'd imagine the sdcard / wireless charger would fetch a higher price if sold separately, but either option would likely fetch close to the same price overall. Also, look online to see how much the camera is going for. The prices of those plummeted on eBay when the S8/S8+ came out and people started getting their freebies.
As for Swappa vs eBay, always Swappa, IMO. eBay charges 10% fee on the sale price plus you still pay the 3% fee to PayPal. You can at least charge the buyer for shipping if you want to go that route.
with Swappa, I think at that price point, it's a $25 flat fee to sell and then you pay 3% to PayPal. But, you will have to essentially include the cost of shipping in your sale price. But it still comes out cheaper than eBay.