The base price shown is for the lowest cost VDO sensor in the list of those available above. The additional cost depending on the type of sensor chosen is shown on this list and is in addition to the base price.
The VDO Pressure Sensors shown above have 2 terminals: firstly a single output with a 0-5 BAR range, suitable for 5 Bar VDO gauges and a second terminal for the earth connection. The resistance output is ~10-180 Ohms.
"Insulated return" means that the sensor has a separate insulated connection for earth.
(Earth Return sensors or sensors with a low pressure warning contact are listed on the product page separately.)