You are missing the point, when was the last time you went out to buy biowaste? The colonies want to get rid of it, and noone will take it for buy price nor will they take it to make small profits of 50Cr a ton for the distance. So they have to offer the large sums.
Lol. You've got thousands and thousands and thousands of square kilometers of pristine planet surfaces, access to practically unlimited energy, and shipping the stuff off-world is the most viable solution, rather than just digging a big pit somewhere and dropping the stuff in?
OK In certain environments that need to be kept pristine, paying someone to haul excrement off-world may be viable. And agricultural worlds might need fertiliser. And some people may want to recover sulphates and nitrates from waste. Or use it as a fuel source but...