Quoted from pool state, not a quoter, and the floor allows 1% of slippage. A trade large enough to cross a tick boundary fills below the figure above.
The 3% buy tax is taken by the token out of what the pool sends you, so the amount above is what actually reaches your wallet.
The 3% sell tax does not come out of your USDC. The pool has to receive the full amount or the swap reverts, so the tax is charged as extra tokens taken from what you have left afterwards, capped at that remainder. Selling your whole balance leaves no remainder and so pays none.
