Don’t be a lazy shipper
If you’re selling on eBay you get a 1099 tax form. That means you can write off anything business related that helps you earn income. ie: - Gemini mailers - Painters tape - Your office (square footage subtracted from mortgage/rent) - utilities (water/electric/internet/ac/heat/etc) (same percentage as office) - shipping costs - even car/gas/etc for travel but that’s iffy depending on how far you travel to your suppliers and where you ship from - more
There’s no reason to be lazy and not properly send stuff nowadays, especially expensive/grail books. You can write off so much… do better.