If you can find the dough, it's usualy frozen and will keep frozen for quite a while. Since I don't buy shredded wheat, I don't know how the prices compare.
The khadaif dough has to be fluffed and spread out in the pan. I can't speak to the relative fun factor.
If I could get the real thing, I'd prefer to do so. But that's just me. I think you should at least try the real thing to see how the preparation differs and to judge the taste and texture differences. Then you can decide for yourself if the difference is important.
The basic dish is relatively simple to make so I can't see the cereal saves you a great deal of time.
The dough is shredded and folded up in the box. You have to go through it and make sure any clumps are spearated and fluffed up. Then you spread half of it in the pan, add the filling and top with the rest of the dough. Then you bake it until the top is a light golden brown.
Add the syrup and you're done.
"If you want to make an apple pie from scratch, you must first create the universe." -Carl Sagan