Until the auction has ended, its not a good idea to try and buy them outside of Ebay, if he reports it to Ebay, you will get booted off.
Also, it would be tricky for him to remove an auction without good cause, and ebay dont like "I sold it elsewhere"
I would sugest, if you are comfortable with the price, bid, and see how you go, otherwise, hope that it goes un-sold, then call, but the second method means you may miss out.