Shao Qingfeng possessed an astronomical amount of resources because he was the person in charge of the Right Palace Master's black market in the outer sanctum. However, he still had to transfer these resources to the Right Palace Master.
But, secretly keeping some of them for himself wouldn't be a difficult matter for Shao Qingfeng, and as a long time had passed since he would have starting doing this, it wouldn't be strange for him to have accumulated a great amount of wealth.
However, most of those resources were useless to Su Yu, and even if he sold them all, he would gain just 100,000 crystals. The most crucial thing was that it would take him a long time to deal with them all, which meant that his gains wouldn't be worth the effort required.