angel_baby01, I'm sorry but where the heck did you get those prices.
Unicorn Mount: unknown. As said above, it hasn't been released in ages so it's going to be very expensive if a person still has an unbound one.
Seraph Wings: 700G (non stat) ~ 2k (Prime). Last I checked, the wings are cheap even if they aren't around as much. It may take some time trying to find a seller but still a decent price.
Mysterious Crown: ~4k. Even though it's around 4k, it's taken people forever to sell them. I've seen some vendors trying to sell it at that price for days and still no success.
PS: Sapphire server.
IMO, this thread shouldn't be here in this section. We have a Barter
forums where in you can definitely check out and ask out.
In such case I agree with lildeviruchi.
I've seen one selling Crown (Prime) for 2.5k last week from the original price of 5k-7k on the first released.
Unicorn (Prime) are rarely being sell or even posted on stall, but talking about market price it's 4k-6k Price now from the original price of 9k-12k.
Seraph Wings (Prime) This is old but people still sells it on the same price range. 2k-3k. Even Less if the person selling is desperate.