Take the height, width and age, as near as possible, and call a local nursery, with little explanation, asking if they know where you could get such a tree or what they would charge for one they have. Of course putting it into the ground would be additional, but they should tell you the total.
Surprisingly, some nurseries are reluctant to kill big trees that never sold, and would give a good price, just to get the room in the nursery for new plants, smaller, cheaper and more likely to sell.

Post this on the conifer forum - the regulars there are extremely knowledgeable and they might be able to give you an answer.