Hi Adriano,
Aren't there lots of properties published with property_lease=rental? If I go to this page: http://balimoves.staging.wpengine.com/bali-property-for-rent/, this view returns all the rentals. If I just click submit on the main search form, the view returns no rentals. I think there's something wrong with the parametric search. I don't think it's the data, I think it's the query. Having looked that the sql query from your debugger, it's asking for the same property_lease. When I remove the second set of price fields (sale price fields) from the parametric search url, the query returns all rentals (http://balimoves.staging.wpengine.com/bali-property-search/?property-lease[]=rental&property-type[]=&property-location=0&rentmin[]=0&rentmax[]=99999999999&bedrooms[]=0&bathrooms[]=0&wpv_filter_submit=Search+Listings).
I need some way of making the query ignore the set of price fields that is not relevant, ie, on use the sale price fields for sales and only use the rent price fields for rentals. I guess we can either do it through js on the form, or with php in functions or one of the views fields. Either way, I'm helpless! 
The other issue I have is with the disappearing input fields. If I run a query for 'buy' properties and on the results page, select 'rentals', the price fields are hidden. If I the toggle between sales and rentals, the price fields do return. It's just the initial state that seems to cause the price inputs not to display.
Thanks,
Tom