Not trolling. I'm just exposing this is how rounding works in many scenarios. Even when you pay taxes at your store.
OP was selling, this small transaction rounding problem doesn't happen if you are buying BTC, only if you are selling in small chunks.
Just try it on the exchange and you will see.
Not true. Say you place an order to sell $500 worth of BTC (or $5,000 or $5,000,000). The fee is rounded on each trade that executes against it. So if 1,000 $0.50 buys are made against it you don't have a single $500 sell you have 1,000 individual sales of $0.50 ea (that are all rounded up). In any exchange you can only control what order YOU place not what orders the counterparty will place. The size of each individual trade is based on the orders on both sides of the book. The fee is based on the size of the trade not the order.