If you're talking about the guy that has been listing his for $500, I already upset him through CL by offering $275! I saw he just relisted on eBay for $530.
It's only worth what it sells for.
Naive or newbie sellers get all butt-hurt if somebody offers less than the princely sum the seller thinks he so richly deserves.
A suitable quote
If you have patience and diligence, you can find what you want without losing your shirt.
My starting rule of thumb is, pay no more than 66% of new-discount price for main stream items.
This does not apply to collector's items, or out-of-production gear.
eBay really has their way with sellers.
I got banged an Insertion Fee for the ad, then a commission when the item sold.
My mopar-trading buddy says eBay is now asking a percentage of your shipping fees as well.
IMO, eBay is the place of last resort, and certainly not the best for sellers.