Cheapest is not always the best. I've renamed your thread title to better reflect your requirements.
For a start, you can state a budget that you are comfortable with. From there, we can help you by recommending species within the range. Don't forget, one species can command differing prices from S$4 to S$480 just because of color variant or location variant.
But if you have no money at all and maybe can only spare S$2. Then this species is 'technically' still in the Apistogramma genus.
Take note that you will not be able to get the female for this HYBRID and they will most likely not breed true.
Alternatively, you can consider Holland rams (Mikrogeophagus ramirezi) or Bolivian rams (Mikrogeophagus altispinosus). They also cost below S$4 on the average and are still considered dwarf cichlids
Most of these species can be found in common LFS in Clementi, Tiong Bahru, Serangoon, Yishun, etc.
Cheers,
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