The thing is, we don't know how much it's worth, the seller also doesn't,
it's worth as much as someone offers, how can you get the maximun amount of exposure?, through it's marketplace listing, so they list it at a ridiculous price so buyers will send their offers through PMs.
You guys also have to consider that things are really really really expensive now, the top tier items of this CI have a LMP of above 100m and their ABPs are above 80m, can you really blame the owner of the pet that took 5 days to appear for wanting to get as much as they want out of it?, the CI pet's almost always the most expensive item out of the CI, check how much the top tier items are and try to come up with a "fair" price for it.