How much money to bring to BMTH concert?

I am going to a BMTH 음악회, 콘서트 in 6 days:) They playing with We Came as Romans, A 일 to remember, and Pierce the Veil:) I was wondering how much money should i bring i want to get like a 셔츠 또는 a jacket. What else do they sell and how much is it?