Below are the available bulk discount rates for each individual item when you purchase a certain amount
This Humidity Sensor is a very simple and inexpensive device based on a capacitive cell (capacitance value chances according to humidity). It is a inexpensive option to add humidity compensation to a project that doesn't require a very accurate Humidity value reading.
You can download the full datasheet from this link.
This sensor is also sold by Parallax and they developed nice documentation and sample code available at their website here.