u/FunAd1331

I've recently gotten into selling TCG Cards on eBay and I'm enjoying it a fair bit. In Indiana eBay will give me a 1099 once my income reaches $20,000, which I'm very close to. After that I know that I'll have to pay taxes, but what will be the easiest way? I make over $100,000 with my day job, so will the taxes I pay for the eBay sales be based upon that income, or based specifially off the eBay sales? Would it be easier to start a small business instead, or would I be paying the same? Any info is greatly appreciated!