Quote from: Genemind on April 27, 2019, 04:29:09 AM

It depends on the coin that you're using to transact.

It's obvious that OP is planning to use Bitcoin since the thread is posted here and he didn't said anything about altcoin. If altcoins have RBF you'll rarely use it and they only have a small time to double spend because altcoins usually have a faster confirmation time than Bitcoin.

Quote from: Yakamoto on April 26, 2019, 05:14:43 PM

Assuming that you don't immediately exchange the product and you wait for the actual transaction to go through and be completely confirmed, you won't have to worry about replace-by-fee fraud. Considering that it only takes 10 minutes to confirm the transaction, I'm sure the customer could wait that long in a worst-case scenario. The only real way to prevent RBF scams is to wait for the original transaction to be confirmed, but the chances of it occurring are actually quite low. I wouldn't be significantly concerned about it.

It's not always 10 minutes though and that's probably the best case scenario if there's enough fee in the transaction.