Maisent,
it shows you have not done this before, so i am gonna ask some positively criticizing questions, to maybe give some valuable tips about things you haven't thought about yet:
1: it's best of 3, but does the system involve points, will all duellers fight each other for points, or will the one who wins 2 fights against the other go to a next round (since that is what best of 3 means)?
2: if a winner will go on to the next round, how are you planning to do that with 10 contestants? the 2nd round will have 5 contestants, which is an odd number, who will fight who then, and according to what system?
3: numbers 1 to 5 will go to the top 5 championship you say:
a: what is that?
b: once again an odd number
c: will it be held on the same date? and if so, don't you think it's weird that the number 1 has a chance to become the number 5 in that championship when held on the same day?
4: it's probably not allowed, but not said: is magic allowed?
5: about prices: armors and weapons the winner wishes: i don't think you can do that... Suppose i wish a full GM platemail set, or a full set of serpent's ... armor of seduction. I really don't think you can provide those.
side note apart from the positive critisism: i already said so in game that organizing and/ or promoting a tournament when preparations for another one is already going on is considered not done by the majority: how very thoughtfull, considerate and respectfull of you to have posted this the very next day i said that 
Perlan, Grandmaster of Masters of Move
Organisor and referee of several succesfull duelling tournaments