To be able to take 11 levels in a 10 lvl prestige you have to be over lvl20. you can't jsut make an 11th lvl just because you want to. You have to use levels from actual classes till level 20 so, no, not even a 14th lvl Master specialist could take it, he would have to find 6-7 levels in another class till 20 and then take the 11th level