In concept it's not, but in trying to get precise credit figures it is at times.
Payout for planets/moons is based on 1) body type and 2) mass of body. Formulas on first page of this thread. Not surprisingly, Earthlike Worlds and Water Worlds are the highest payouts.
Complicating factor is whether the body is tagged by game as a terraformable candidate. If it is, sometimes you get a substantial bonus for that, sometimes not. Thst's what redfox's chart is about. Not 100% predictable at this time based on data available to us, the players. Substantial middle portion of this thread discusses that.
Lastly, if you scan a currently-untagged body and are the -First- to sell that data to cartographics, you get a 50 % bonus of it's base value. PLUS you're considered the discoverer and that body will be tagged with your name forever.