Yes but part of the appeal of crypto is you don't have to use payment processor.
If going to have the money flow through a third party anyway, why deal with the volatility?
Because volatility is temporary, while increasing value is permanent. For fiat scrip, decreasing value is permanent. I'll leave the math to you, detective.
Joe empties his phone. Sends half a btc to his phone as dust inputs. Goes to Raley's, all his inputs are dust resulting in a very large kb transaction of fresh dust - which he doesn't pay a fee on. When will the transaction be confirmed?
Meanwhile his shell script detects the spend, waits for two failed confirmations (at which point Joe is long gone) and then double spends them with a transaction fee.
Miners see the transaction with a fee and confirm it. Didn't cost Joe anything, worst case scenario is some miner confirms the first spend and he pays for his groceries. Normal scenario, he's already in his car by the time the next block happens and long gone by the time the grocer sees 2 blocks w/o a confirm.
wouldn't it be fairly easy for a merchant wallet to check for this type of thing. If any of the above scenarios are true, then the customer would have to wait for full confirmation. Basically, wait 10 seconds, have the merchant wallet check for double spends. 10 seconds is enough of a head start that the first transaction should be propagated to enough of the network to make double spending unpractical.
Satoshi addressed this here. Are there any flaws in his plan?: