A spirit vein that spans several miles is indeed a huge challenge to transport, even if it can be dug out.
The demon cultivators from the Western Region invaded the Eastern Region, extracted the spirit veins through brute force, breaking them apart after excavating them to take the mother ore, while the rest of the spirit crystals were stowed away in their pouches.
Thus, attempting to cultivate a new spirit vein solely from a mother ore would take at least several hundred years. Naturally, this drastically depreciates their value.
Chen Dengming did not wish to drain the pond to get at the fish, nor did he want cultivators from the Northern Region to invade the Southern Region and seize the two first-grade spirit veins in his possession. These veins were his fundamental assets.
While excavating the spirit veins might be feasible, it would be difficult to transport them without damaging the veins, unless he returned to his sect and borrowed two large fourth-grade spirit boats.