Question About Camping on Colorado?

Me and my friends are planning a trip to Colorado somewhere in middle of june. Upon much research, I narrowed it down to Mueller State Park, Rocky Mountain National Park, And Bear Creek. However, in addition to the camping fees, i didint know that you had to get a State Park p. I know how to get them, but we were planning to stay for 6 nights and seven days. They have only annual pes that go for $60. So im at a crossroads on whether we should go for the state park, or go somewhere else. What do you guys think? Any suggestions or comments would be greatly appreciated.