In Aswan, as in all big cities in Egypt, you will find all kinds of accommodation. Only the top hotels can be recommended, though. There is a big difference of services between the middle priced hotels and the top ones. For a little more, you can get one of the best hotels in town.
If you want to stay in one of the cheapest hotels, you will find a place to stay very easily. If you come by train, many locals will offer you a place to stay at the same train station. You just have to negotiate the price. If you come to Aswan soon, you can take your time; and visit two or three hotels before making a decision.
Most of this city visitors do not sleep in hotels though. Where do they sleep then? In a boat cabin.