Congratulations on your registration of oneplacehealth.com and oneplacedental.com. Both have visual and verbal appeal. They both read as domains a medical corporation with the name OnePlace would hold. Both domains align with a franchise of health-related services that might be offered by a single-entity.
With regard to ideal sale pricing, it ultimately comes down to the manner in which you let the market know they’re available. With general listing, you could stand to profit a few hundred and upwards. However, marketing them as a franchise of services (assuming there’s no trademarks) could bring in significantly more.