What someone prices anything at is their business not yours...

You're alweays free to engage them in a private negotiation in which you can explain why you think something is over-priced and what your offer is.
They are then free to accpet or reject your offer...

If they reject it and no-one buys at it, then inevitably it will come down to price that someone will pay.
If you never see the item again, then either you were wrong and it was worth more than your personal valuation or they've decided to sit on their 'investment' and you still won't get your hands on it.