Why are some Disney movies more expensive?

[Movie shy]

Hello everyone,

I have always loved Disney films but they seem so expensive for their blu ray's. So far I only have 4 Disney blu's. Have the following: Enchanted for 7.99, Sleeping Beauty the Platinum edition used for 5.99, Alice in Wonderland and The Rescuers/Rescuers Down Under both 11.99. Felt like those were good prices on blu. Why does Disney have some titles that are very expensive and other ones that are cheaper? I know that Disney often puts movies in the vault. I so want Beauty and the Beast but it's in the vault and if I tried to get a copy from a reseller on Amazon it could be 80 or 90 dollars and will not buy for that price. I would like to buy Peter Pan and the Little Mermaid but the most I want to pay would be 19.99 new and they are always more expensive. I wonder if Disney has different prices depending on a tier of a film's popularity. I have noticed also that when they re-release blu ray's they have cut way back on their special features. My Sleeping Beauty and Alice and Wonderland have great special features but not the same for my copies of Enchanted and The Rescuers.