I hate to say "So in EVE"... but in EVE, all player-delivery contracts paid based on volume and distance. I just went back to site of one of the most reputable player shipping services in the game. 845,000m^3 of goods (can only be carried by the biggest cargo freighter in the game valued =~ 1bn credits) delivered two jumps will pay a meagre 7m, with a collateral of up to 1.5 billion.
That is, you can set a contract for up to that much volume of goods, and the hauler pays you 1.5 billion credits in security to deliver it, and you return that 1.5bn on success and pay the hauler just 7m credits. Elite logic, you'd be looking for a payout of over 1.5 billion. Hauling simply doesn't work that way.
180t of biowaste and 180t of Palladium should pay roughly the same, maybe with a 10% surcharge on the Palladium delivery, because regardless of what the cargo is, shipping it is identical effort. Heck, at least you don't have to pay the collateral up front to take the Palladium delivery.
Note: Bear in mind EVE is a game where literal hundreds of billions, even trillions of credits bandy about, but a haul mission of that magnitude and payout is very much worth it.