Someone is trying to sell me 2expensive Cisco Routers cheap! How do I check the registration in case stolen?

Call Cisco and tell them the serial numbers. If it's been reported stolen, then they should know. My guess is that they are stolen and I bet they don't know the admin pwords anyways. Furthermore, there are a variety of Cisco routers that do different things. They are noting like the routers one can get at the consumer level. Leave the Cisco hardware to IT professionals.