Yes, it costs money. But V-Ray 6 is vastly superior to 3.6. It includes:
: A clean, responsive interface with better asset management for materials, lights, and textures. The Hidden Risks of Google Drive Download Links vray 36 for sketchup 2018 google drive
: Simulates realistic atmospheric depth and haze. Yes, it costs money
Source: Chaos Group Official Documentation vray 36 for sketchup 2018 google drive