When I set up my first tank after a tester coral I got locally to make sure everything was ok, I bought a 20 frag pack pretty cheap. It got may tank full and everything went fine. I did regret it a year or two later, some of them turned out to be awesome, most were kinda meh. I don't really have an outlet for things so I wound up with a lot of corals that I didn't really "love". So there was no negative with adding them in that kind of volume, but in hindsight I wish I had only picked things I really liked.