"It is 11000 yen."
いちまんいっせんえんです as i remember, but Windows IME suggests that would be 一万一千円です I am not sure about how it is written, but I remember that one thousand after "man" is always spoken as issen instead of sen.
What you write is exactly what the IME suggests when I type いちまんいっせんえんです and I remember that after "man", it is "issen", so you might be right. Maybe someone can tell?
I was erroneously thinking you can't say "ichi man issen", when actually the more I thought about it, that's what people usually say when speaking. The problem is that when writing people usually don't put an 一 before a 千 that is preceded by other numbers. Some quick googling came up with this hinative answer.
What does 万 mean again? It's kind of frustrating that you only see the English meaning once if ever while learning words here.