PwC non-ACA role

Hi,

I've been made an offer for a graduate scheme for data and analytics in assurance where I will be joining their IT risk assurance team. I'm aware that, having done a graduate scheme at one of the big 4, you're in a great position to move to other jobs also. I was wondering if this is only the case when you're doing accountancy and completing the ACA exams. I don't complete the ACA exams in my graduate scheme so I was wondering how this will impact my employability later on? Furthermore, I was thinking about paying for and completing the exams myself anyway, is this a realistic idea (I'm not sure how much it would actually cost me)? I'm probably not going to want to move into investment banking anyway, but it is always nice to know you have options.

Thanks in advance.