It is not about the expense of the fish, that is a big problem on this board, it is aout the FISH. A lot of people get some sort of ego boost by posting their supposed exotic fish, in a month they have moved on, no real love for the fish. Just the little bit of attention they get by having something they feel makes them cooler. It is really a shame.
Enjoy your fish, that is the key.
BTW your "common" carpintis looks exactly like one of the "exotics" that is the cream of the crop right now. Do something different raise your "common" carpintis to adulthood, nobody else will, they will trade it off in another month.