If you are not short of money, you can try to sell large equipment because of the high profit. Of course, the main thing is to contact the big leader, because the equipment is expensive and the big leader has to ask questions. But expensive equipment does not need to be updated frequently, and hospitals can't stand it.
Personally, I suggest you start from an early age. After all, you just did this, and gradually accumulated experience. After all, you have to support yourself. You know many people, have a wide network of contacts, and have a thorough understanding of the small market. You can try to sell big equipment in big markets, which may do better.
Of course, there are also some luck factors. Maybe you are successful in selling large equipment, but who can say for sure about luck?