no mate, i fell for the same thing some time ago. Bought Reub and found out that the monitor had 3 years on the service tag, was so happy and rang up to get have the monitor replaced because it had developed a fault. Only to find out that it was registered in someone else's name. When i did find out the name person who it was registered to(the seller did not know the name and dell would not tell me either, it was nothing short of hell for me to get this) they told me that i cant get the guarantee as i need the original order number that it was registered under. So i sent the monitor back and got a refund and bought a new one.
anyhow check first to find out if it has been registered under someone else's name, as they will be usually if they are refurb.