Rahman had played a key role in Bangladesh's famous home series win against India last year.
"It feels good. I was hoping I would get the opportunity. Everybody was saying I may be drafted this time," Mustafizur was quoted as saying by bdnews24.com today.
He is hoping to match the performance of his seniors in the cash-rich league.
"Shakib (Al Hasan) is doing very well (in the IPL). Mashrafe (Mortaza) and the others have played too. It feels good that I will be playing there too."
Asked about his price tag, the lanky left arm pacer said: "I have nothing to say about the price. I never thought about how much I could get. I just wanted to play - that would be a big experience. I'm just happy to get the opportunity."
Mustafizur will rub shoulders with the likes of Yuvraj Singh, Shikhar Dhawan, David Warner and Ashish Nehra in the Sunrisers unit.