As pointed out by others, it depends on the individual fish.
What you need to do is have a "plan B", just in case the fish doesn't work out. Usually this means selling or giving away the fish to someone else that has a FO or FOWLR system, or returning the fish to your LFS.
While we are on the subject, always be careful about any information you get from a LFS. All too often they are going for the quick sale, or are just not knowlegable about SW reef systems. A short post here just might save you a lot of time, trouble and money.