Dobsonian’s are heavy telescopes. Their weight can range from 22lbs(10kgs), to 75lbs(34kgs). By sacrificing portability, they provide the most power per dollar. They make amazing beginner telescopes.
Catadioptric’s are mostly for advanced astronomers, consequently costly. They are mostly automated, which is convenient for tracking planets in the night sky.
Refractor’s are the most price efficient category. They are easy to set up and carry around. As for the image quality, they are considered modest for the price. But still, they may be a worthy choice for some.