Bought mine at LFS
There were three juvenials left in a tank. After observing for a while I noticed that two of them(one slightly bigger) hung out together behind a rock and kept the third away. Based on all I had read this was suppose to be how pairs formed, so I took the chance. Both fish were under $30 togther. Now it is hard to find single clowns for under $30.
There was a liitle agression at first in the new tank, but they then settled in. Over two years later the female in now about twice the size of the male. I recently aquired a BTA and they rarely stray far from it.
These are my favorite fish for personality and appearance by far. Watching them interact and feed the anenome is amazing.
If you have a large enough tank another option would be to purchase 3 or 5 small juvenials(start with odd #) and let them mature. Good chance you will get 1 or 2 pairs. Just have a plan for what you will do with the odd fish out.
, buying a pair is too pricy and most of the time there is no guarantee, unless you stumble across a fellow hobbyist looking to sell an established pair.
Keep in mind in your 55g one pair would be all you could keep long term any additional maroons could not stay. For future planning also keep in mind it is not uncommon for maroons to get 6"+. I saw one over 8" in a LFS
display before. My female is approaching 4" now.
FTIW, it is true that maroons do have the potential for being teritorial and nasty if crowded. My pair definately rule about 1/3 of the tank.
Also, not sure if you plan to keep the damsels, but they could be an issue introducing any new fish.
Let us know what you decide to do.