Explorers of praetoria have returned to their home lands with fanciful stories of the lands they have visited ... a rough map of the vast continent has been created and wealthy citizens of the Splinterlands have rushed to own a piece of these lands sight unseen. It has been well over 2 years since the first explorers have journeyed to praetoria and agreed to sell off large chunks of the land while leaving many plots open to public use, conservation or for the previous inhabitants. Now groups of surveyors are returning using some of the funds from the land sales of years past to survey and classify the lands of each of the 150k plots of land.
Thus the surveying of the land is a free exercise that was counted as part of the original cost. However it is noted that with the vast amount of land to survey these crews will be working quickly and they are unexperienced crews of surveyors, seeing that their homelands have been mapped and surveyed for hundreds of years if not longer. The work and skills of this group of free surveyors is being lambasted as simply not adequate for some of the new owners of Praetoria who are launching a campaign to enlist an elite team of Dark Elvish surveyors who will use their astute understanding of the lands and magical powers to do a much better job recognizing and more importantly documenting and classifying the new land of praetoria. Their services are not cheap and we these teams will demand 20k Dark Energy Crystals in order to survey the land... they say the Dark Energy is needed for the actual process they will use in their investigations into each of the plots.
For their work there is NO guarantee of success as some land is very straight forward and even the original surveying crews would get it right. But the dark elves are guaranteeing a doubled chance your lands are more rare and valuable. Not a doubled rarity but a doubled chance of an increase in rarity.
What does a more rare land mean... it means greater production of the land and while the actual production increase is not specifically known it is said that it could be very worth your consideration of hiring this elite team to survey your land.

(This is the part where you can also share some thoughts about what increased land may be able to do and perhaps in less specific but interesting storytelling fashion)