oh joy! it's a MethodInvocationException!

Message: Invocation of method 'getTotalPrice' in class gr.netmechanics.platform.rentacar.site.BookingHelper$Proxy$_$$_WeldClientProxy threw exception java.lang.NullPointerException at WEB-INF/vm/page/booking_step4.vm[line 149, column 68]

Reference name: number

Method name: getTotalPrice