If you’re in the market for 3D rendered images or visuals, then along with your expectation, another primary concern is the cost. Your requirement and expectations will depend upon how much you can spend on creating/recreating 3D rendered designs.
First of all pricing is vastly different for different industries. Construction and architechture require more detailing and virtual 3D tours, therefore, the pricing will be higher. 3D rendering of a specific image or product might be cheaper. Likewise, recreating furniture samples is also easier, and therefore cheaper. Check this link for some pricing guidelines.
The price for 3D rendering is also affected by the length of the rendering time. This, in turn, depends on the amount of detailing you want in the image. For example, if you are rendering an outdoor image with good lighting, it will render faster, indoor scene, especially, let’s say a whole room layout with background, tones and shades will take longer.
Some companies charge on a per image rendering basis while some charge per project. You choice will depend upon the volume of work, i.e. the number of visuals to be rendered. Then again, for a small job or specific presentation, it’s best to hire a freelance designer. They tend to charge lesser than companies and you have the freedom to decide a pricing model that is comfortable to both parties.