Sometimes you will receive more money then you ask for (for many different reasons) and the buyer will ask you to refund him the difference – and generally you’ll do so immediately. However, a few days later you’ll receive a notification that the payment you expected to receive did not clear. And you’ll be still sitting on your gear minus the difference that you refunded to the scammer.
It’s a common tactic used on all classifieds websites - not just seabreeze.
Tip: get in contact via email with the seller (don’t use the PM on seabreeze) and you’ll be able to trace the originating IP address (just google it how to do it) and you’ll find out if the email is sent from some other place than the seller claims to be e.g. Nigeria. Most scammers don’t use a proxy so it’s easy to find out what country and region the email is sent from.