Negative Price Option - Reduce Bundle Pricing Based on Service Choice

Example: Choice between 3D Tour options.

I would like to set preference to a specific service but it is more expensive than the other. Giving the option to choose via “Questions” works though introduces human order error if they leave default cheapest option and again, not the preferred choice. If I could default the service of choice and then reduce the bundle price should the client select the lower priced service, this would be my preference!