Colt Peacemaker Buntline 22

I am looking at this little Colt, and am wondering what it is worth. It has a 7 1/2 inch barrell and is in great shape.(98%)
It has both 22lr and 22mag cylinders. I don't think the 22mag cyl. has ever been used. The gun looks great. The blueing is very nice.(like new)
How high should I be willing to go on this little beauty. I think it was made in 1975.

If you have Barnes and Noble or some other book store in your area go in try and find a book on gun values. I saw one the other day. If I get back over there a will look for you and try and get you a rough idea. Or go to gunbroker.com and look around on there.

I just went to gunbroker and they have some on there. Check it out.