I am booked into the Tanes Hotel Guest Room for Friday and Saturday night. Seemed to have decent enough reviews and for a total of £76.94, looks a good deal to me. It is on the other side of Cardiff but only a 12min journey according to Google maps.
As I am driving up, I can offer lifts to or from the casino for anybody that wants one. I guess i will be on a similar route to other peoples hotels so little point in wasting money on taxis.