I had to about 3 years ago. I called different imaging places asking for prices until I found the most reasonable. It was over off of Judson and 35 by the hospital and was under $500 and if I remember it was closer to $350.
i did one at STRIC (South Texas Radiology Imaging Centers) at Med Center. probably depends a lot on what contrast/imaging/body part/etc. but I don't think it was more than 4 hundo