Only accounts with good feedback get hijacked.
The major tip-off is the request to contact the seller outside the eBay system. I seriously doubt that the email address listed puts you in touch with the seller. If you send an email to the address listed, the scammer will ask for you to send an international money order (possibly not even to an address in Canada, where the seller is ostensibly located) or to otherwise pay outside the eBay/PayPal system.
Also, look at the other items in the seller's transaction history. This guy sells toy soldiers and saxophone parts - not another photo-related transaction in there.
Finally, there is a legitimate way to "end the auction early" - with a Buy-It-Now option. The average recent price for the 75mm Summilux on eBay is $2,300, so you aren't likely to see a BIN price of $1,000 or even $1,500.
But then hey, maybe the seller is just uninformed, Or maybe the lens belongs to someone with whom he/she is ending a relationship. You know - like the apocryphal divorce Porsche for $1. Riiiiight...
- John
Edit: composing the above while Kim was posting - wise advice there, Kim.