I don't know where you get that from, the warranty card plainly states that they will repair or replace the scope at their discretion regardless of whether you are the original owner or not.
Repair or replace at their discretion isn't the same as Leupold's warranty. I know this because I had a Monarch UUC 2-7 power that I bought used that would not hold zero. I sent it into them and guess what they wouldn't repair or replace it, they did offer me a refurbished scope at a discounted price. That is what their discretion means. Leupold has gone through and fixed every used scope I bought that I had questions about for the price of shipping.
Another good indicator as to how good the scope is take a look at the used prices on scopes. A one generation old Leupold scope will bring at least 75% of the cost of a new one. Two generations old will bring around 60%+, because if they can't be fixed they will be replaced with the current model by Leupold. Nikons are usually around 50% or less than new if they are the older generation scopes. Why do you think that is?
Nikon scopes range from $209 to $400? while Leupold range from $299 to $2000 or somewhere in that vicinity, you do the math.
I've done the math on both several times. I own both scope brands still and I can tell you that Leupold is more expensive because it has a more extensive line that offers more features. Plus with the new Redfields made by Leupold with the same no questions asked warranty you can get into a decent hunting scope for less than $150. You can still step into a Leupold for less than $200 for the VXI and less than $300 for the VXII or you can exceed $4000 for the MK8 depending on your needs.
The Nikon Buckmasters max out over $350, Monarch's exceed $400, African models max out at $800+ and the Monarch X can cost over $1000. Where did you do your research as your math doesn't add up. Realisticly in the standard scope powers the price difference is more like $100 than half you stated when you use compareable scopes.
Bottom line is I've received far better service from Leupold than I have with Nikon. So I've stopped buying used Nikon optics. Do I think you will go wrong buying a new Nikon? No, I think they are good optics but I've only had experiences with the Monarch line of scopes. I do however think that they are on average heavier, they don't have as nice of a profile when mounted on hunting rifles, and in most cases and the eye box is more critical on them than Leupold.