I know you asked specifically about Casper, so if you are committed to stay in Casper, just ignore this. But another option is to stay in Alcova. My Dad and I hunted 63 a couple of years ago and we stayed at a little place in Alcova for a night. They have some cabins there behind the Sloane's general store. You can google the store or Alcova Inn or something like that and find it. They had a kitchen and were clean. If we were going to that area again, that is definitely where we would stay a night or two. We usually camp much of the time, but it is nice to get a room and have a shower occasionally. We liked the place and it was definitely nice to be closer to the area than Casper.
Long story, but we had to make an unplanned trip back to Casper during our hunt because of a vehicle problem. We checked Alcova on our way out and they were booked (so if you plan to stay there you will need reservations, they said they fill up in hunting season). We ended up staying at one of the Super 8 motels in question I think. I would have to look, but I know I saved a business card because it was really reasonably priced and they had a good breakfast ready very early. They definitely catered to a hunting crowd. Of course, now I am wondering if I had coffee in the room and I am just trying not to think about that. Heck, I try not to think about what nasty things might go on in any motel room where I stay!
Good luck on your hunt. Let me know if you need any info.