I hate the "what we have is out" speech.
That's when you have to bring in the big guns.
A little name dropping, glibly mentioning in passing about the obscene inheritance you received, the "It's a bloody shame I have to go to Dubai tomorrow, they'll probably have one THERE". Like, um, "I saw one so similar at Taylor Swift's party in Vail, it was just like the one Paris had in her Central Park place. Little did I know Grandma invested in Apple and played options, as luck would have it, I was her favorite! I didn't realize it until her attorney read the will, (sigh). Oh well, this time tomorrow I'll be in my jammies and slippers en route 18 hours First Class to Dubai. I guess my current collection of 853 extension cords will have to do."
Watch them scurry like squirrels hoarding nuts for a deep freeze. They'll bring out cords you never knew existed. But strong. Be firm. ID the best of the best and offer 40% of the price. When they hem and haw, remind them they told you "what we have it out", and begin to walk. They'll pretend they'll get fired for meeting you halfway at 50% of the quoted price. Take your time. Watch them sweat. Look at your watch and then say "you know, first you say these basically didn't exist, and all of a sudden they're half price. Obviously I'm being jerked around. I offered you 40%, and that's probably too much. I'm not paying a dime more. At this point I'd pay full price in Dubai, because I can. I have to go.
Before you know it, they're ringing it up at 38%, including tax, and you go home a happy and savvy extension cord owner. Whether it's #854 or your first, congrats!