Lease or Buy Core Network Hardware

Leasing is a fancy name for "screwing the customer". Look at it for what it really is. By the time the lease comes up, you've more than likely already paid enough into that hardware to pay it off. However, you don't own it, which means that you have to pull it and replace it. That means that you HAVE to spend a lot more money to buy/lease more hardware, set it up and get the whole thing configured...again.

On the other hand, had you BOUGHT that equipment, you now own it. Sure, in three years you no longer have state of the art gear. However, it is unlikely that your needs will have evolved, in three years, to a point where you have to migrate your entire core. That means that, while the gear you have is not the latest and greatest, it DOES get the job done. If it ain't broke, don't fix it.

Leasing just means that you have to fix it every 3 years whether its broken or not.

purchasing is always better in terms of Core Network Equipment. I would assume that you already have some wiring in place, and while not the ultimate determinant, it plays a big role in which technology builds your core. Replacing wiring every threeyears is not the way to go. The beauty of ethernet is that it is scalable. Leasing would be a viable option only if you have a small network.