The lower the realm, the more spirit stones must be paid.
Such an arrangement is designed to discourage low-level cultivators from roaming around; if low-level cultivators were too mobile, many islands would become isolated cities.
Every cultivator wishes to go to cities with more abundant spiritual energy, more experts, and stronger sects. By imposing high teleportation fees, many low-level cultivators are forced to remain in their home cities.
This rule is unfriendly to low-level cultivators, but from the perspective of the entire East Sea Domain, it is necessary. Other domains in the Middle Realities do not have this rule because only the East Sea Domain has teleportation formations on each of its islands.