Peacock Bass or Peacock Cichlid. Be careful though because it's not a bass and there is another genre of cichlids that goes by the name of peacock. The Aulonocara from Lake malawi are also known as Peacocks.
Dude, you need to do some serious research. Peacock Bass, Cichla ocellaris can grow upwards of 30" and weigh more than 25 lbs. Unless you have a 500+ gallon tank you should not even consider these fish.
Also, small Peacock Bass are incredibly delicate and difficult to feed when that small. They rarely eat prepared foods when less than 3" which leaves you looking for small feeder guppies to sustain them.
$2 for a 2" fish is a good price if they are healthy and in good condition. If they are really skinny and emaciated I'd pass as they are more than likely already on their way out.