If you are just looking to take a cow for meat then there is such an over abundance of cows in Colorado that you really do not need to pay for a private hunt. A cow is a cow is a cow. There are no antlers to measure so there is no need to pay someone else for a hunt. They are just about giving the tags away for cows. You could just about pitch a tent anywhere in the mountains and see cows.
Before you decide on paying for a cow hunt I would do a little research for yourself. A good option is applying for the early season cow rifle hunt. It is in September during the rut so locating them is relatively easy.
A good web site for colorado elk hunting and outfitters is
http://elkcamp.com/.
Good luck!