How do find the vase?

In order to find the value of anything you must clearly identify what you have. Look for manufacturing marks. Many older items have multiple makers marks, country/city of origin marks. Some marks are date codes for the time of manufacture.

You need to know the style of the vase and what materials it is made from.

Measure the length, width and diameters.

Until you get as much information as possible, determining the value is impossible.

The final determiner is the condition. Chips and breaks reduce the value on all but the most rare items.