How could late-stage Spirit Refiners be willing to give up 2nd-order cultivation resources so easily? That too in exchange for something that was of the 1st order level?
It could be argued that the 1st-order inheritance was worth the price it was getting exchanged for because it was related to the field of Array Formations.
But one had to consider that the potential benefits of owning such an inheritance could only be obtained if one decided to study it for years on end and achieved a semblance of success in the field.
Whereas 2nd-order cultivation resources that the owner had asked for could be used right away to concoct some rare elixirs out of them. They could at least hire some experts and outsource the concoction process.
However, nobody could hire someone to grasp the knowledge related to a certain field for them. There was no outsourcing when it came to comprehending a subject matter.