By default, WPL uses comma character as thousand separator of numeric fields in search widget. If you want to change it, then you can simply do it by adding fourth parameter into the price, area, etc. fields in the search widget configuration.

For doing this, please navigate to Appearance->Widgets and find your desired search widget (Normally it's included in "Property Listing Top" or "Carousel" positions) and click "View Fields" button. In the opened light-box, find the price field and then add your desired thousand separator as fourth parameter.

The pattern will be like this: min,max,increment,separator

So the final configuration will be something like 0,10000000,100000,.

Please find following screenshot as well.