Ginseng fruit is classified as a fourteenth-grade Heavenly Material and Earthly Treasure, it's hard to imagine what level of treasure would be returned as a reward for granting Ginseng fruit.
Currently, a few disciples are at the Earth Immortal Realm, being rewarded with fourteenth-grade Heavenly Materials and Earthly Treasures, yet there is no system for returning rewards.
However, there are thirty Ginseng fruits, and the Ginseng Fruit Tree can bear another thirty every nine thousand years, so Lu Changsheng isn't stingy about it, casually giving each disciple three Ginseng fruits to extend their lifespans.
Xiao Fan and Dugu Aotian knew they were precious items, and actually, eating one was almost enough, but Lu Changsheng still gave each person three, truly not being miserly.
Lu Changsheng himself also ate one.
The Ginseng fruit could not infinitely extend one's lifespan, and its effectiveness would only diminish over time.