Dear Ahmed,
You've asked a couple difficult questions, and I'm not sure I can answer you the way you'd like, but let me say a couple things. I'm going to see if I can get some help, but I don't recognize what I see in your photo. Perhaps I can find someone who might be able to at least say what it is. That will be a start. Do you know anything at all about it?
Let me say a few things for now concerning your questions. The artistic value of an instrument depends partly on the person who wants to play it. There are instruments some people might really love but other people might really dislike them. Perhaps what is most important to such a judgement is the mechanical reliability of the instrument and its accuracy in reproducing what the player is trying to do. Perhaps if I can find someone who recognizes what it is, we might be able to get some idea of its reliability and artistic value. From your picture, the instrument seems to need a lot of work. The keyboards, in particular, are in very rough shape. It is difficult to judge much about it without being able to actually touch it and see what shape it is in. However, it just may be possible to get it working with some loving care by someone who really knows what they are doing. I would say, though, that it appears to need a lot of work.
Another thing that needs to be taken into consideration, and I cannot answer this, is how desirable such instruments are in Egypt. An instrument may be very valuable in one place but not valuable in another, either because there are lots of them, or because no one wants them. So the answers to your questions about artistic value and monetary value depend on how rare such instruments are in your part of the world. If there are very few, even an instrument that we here might consider to be common or not so good might be worth a lot in Egypt if it is rare.
I'm going to see if I can find someone who might be able to help us more with this. I'm sorry I can't give you a better answer, but let's see if someone else can.
Tom Dressler