Harvesting of the oolong tea leaves by hand is hard work. One characteristic of a good spring harvest is a beatiful sunny morning like the one in video, as opposed to a dreary or rainy morning.
Oolong tea harvesting is done 4 times a year during the 4 seasons. In terms of price and quality, the best in order are winter, spring, autumn and summer harvest. It is normal for the prices of winter harvest to be a few times more than the summer harvest. Moreover, the demand for the winter oolong is very high among the oolong tea drinkers both local and abroad.
As most oolong drinkers are inexperienced in differentiating the different seasons oolong, they may be taken for a ride by unscrupulous retailers who may claim to sell premium high mountain winter tea when the tea sold may be of a different season or may be not 100% pure (a mixture of 2 season tea). I myself an amateur tea drinker have to rely on a good source for my tea....fortunately picking up the tea from the tea owner myself.