I want to buy new speakers for 50,000 and see it used for 30,000, what should I do?

Good disclose where.

You keep acting like you’ve made this 25% off deal in store so give the facts on your deal - brand, model, dealer. Post your system with pictures while you’re act it so we have the proof. Dealers make 20-30% deals on lines they are moving out of and on demos. Reading adds isn’t making chest puff deals.

BTW those Acora's aren’t $50K speakers - $37K

Actually the MSRP on those Acoras is currently $48K depending on finish, close enough. They just happened to be the first example that came to mind since it was relatively recent.

I’m not going to potentially throw the dealer under the bus by exposing him, even though he’s resorting to the same sort of deal making I’ve encountered throughout my time in this hobby. I won’t risk him losing the line since it might create animosity with Acora dealers an adjacent regions. 

And you’re wrong on the margins— dealers usually make more than 20-30% on demos because in most cases they acquired their inventory for half or little over half of MSRP. If they were to sell them for MSRP, that would be 100%. That’s common consumer pricing structure BTW. The reason outlets like Crutchfield don’t offer similar deals is because they have a generally ignorant and loyal customer base. Any independent, single-store, brick & mortar dealer would be out of business in no time if they were only offering discounts between 10 and 15%, especially dealers in the high end market. 

Again, don’t take my word for it, call around to some of them and ask what kind of deal they might be willing to make you on that Magico/Wilson/YG etc. Just because you didn’t get as good a deal doesn’t mean there are not good deals to be had. And yeah, early on in my time I was just as ignorant and bought more than one pair of speakers for full retail. Some dealers will only give good price breaks to repeat customers. But many if not most are willing to do so if you merely ask. Again, call around and ask. If they refuse to budge over 10-20% it’s because they likely think you’re flush and/or already smitten with the product. 

The amount of markdown you can secure when buying used audio gear, like in other markets, depends on various factors including competition and current market conditions. For example, before COVID-19, it was easier to get a 20%-25% markdown below MSRP when buying a car in a buyer's market. However, the situation has changed significantly now.

When it comes to audio gear, in my area of West Palm Beach, there's only one dealer carrying high-end gear, and his prices for new items are fairly firm. However, he's more generous with discounts on used gear, which helps on his cash flow. Negotiating more than a 10% discount on new items is difficult, and it largely depends on the brands.

Like I thought you haven’t made a deal. And go look at the discoun5s offered on demos and discontinued lines versus blathering it's 20-30 %. Look at the Sound by Singer demo sales page as an example. Seeing an add at a discounted price isn’t walking into a dealer and face to face working on a deal on new speakers.  so save the chest puff commentary

The OP needs help making a decision; but, he'd be a fool to reveal the speaker that he's considering because someone more decisive could swoop in and buy the one that is currently on the used market. So, a tough mess to untangle.

@emergingsoul , have you seen the ad on The Music Room website for a pair of Rockport Technologies "Cygnus?" This model & finish lists for $70,000; and, it is for sale for $44,999 (+ 1599 shipping). The last sentence of the Soundstage Network review is: "You can buy these and never look back."

The OP needs help making a decision; but, he'd be a fool to reveal the speaker that he's considering because someone more decisive could swoop in and buy the one that is currently on the used market. So, a tough mess to untangle.

Yeah right ...No such thing in the high end...it is always a buyers market and a desperate seller or dealer