Don't know about Amazon but Ebay has a single checkbox to collect taxes based on the destimation. An online service The STC dot com provides the same for other vendors for about 10 cents per sales. Might be cheaper ones than that one. I have not checked around.
That means filing taxes to more than obama’s 57 states which is complicated
You file with the 50 states plus territories if applicable. You do not file with each jurisdiction.
Yes, the sales tax compliance will eat into your profits. It's easy but you have to pay for convenience.
You are all missing the point. Many of us have stand-alone business that have absolutely nothing to do with Amazon, eBay, etsy, and all. We sell directly. We now are facing taxes to about 10,000 jurisdictions. Sure, maybe some state filings will work but how will we know? If I sell to someone in NYC, they want tax, the state wants tax, and, if I recall correctly, they want my company to register as a foreign corporation. Other states, like Texas, require similar to sell to customers in their state VIA THE INTERNET. Been easy to ignore but now that we are risking tax issues, this becomes a lot more serious.