Why is white tea generally more expensive?

White teas are carefully picked buds. It’s more time consuming to pick only buds rather than harvest the whole plant indiscriminately and it means each tea plant yields less white tea than it would another type. Not to mention I assume they also have to be treated with great care after harvest to preserve the fine white hairs present on the leaves, and white teas with those hairs present are usually most expensive of all.

There are black/oolong/green teas also processed with great care like white and their prices usually reflect that and can be just as expensive if not more expensive.

There are really a combination of factors to the cost of a tea. In the case of white tea, as noted, its simply the bud of the tea itself, with preference to those with downy hairs. It’s also a case of supply and demand with limited white being produced. Often its only from the first flush (harvest) of the year, and demand for the first harvest tea leaves is quite high. All of these things impact the price set at a level consumers will pay and provide maximum profit for growers, manufacturers, distributors, and retailers.