Buying a B-flat instrument depends on what works the landlord needs to play. In recent years, because the works of popular saxophone masters such as Kenneth and David Kautz have flowed into the mainland and become popular rapidly, tenor saxophone is increasingly defined as the choice to play works with popular tendencies, such as Home, Jasmine, Love Forever and Stay with Me for Life. B-flat alto is mostly used to play jazz and classical works because of its rich and varied timbre, among which most works tend to be jazz.
The model of saxophone can't tell the quality of an instrument, and any model of saxophone has its own quality. If you want to buy it, it depends on what kind of works you need to play, or on your usual habits, your breath, your sense of music, and which instrument you are more suitable for playing.
I hope my answer can help the landlord. This is handwritten.