Blaze spawners are worth a lot. Most people don't want to sell them but you will probably need more than 100k for it.
I don't understand why they are worth so much... You can check on the live map and find a fortress and hope no ones been there.
blaze spawners that are close enough together to be classified as a "double" spawners are super rare. And they give you tons of xp.
*Pig* I is calling de Gramar Nazi on you! *Pig* *Calls Grammar Nazi* *GN* Hello sir, how may I help you today? *Pig* We have an improper speaker! We need professional help on this on sir! *GN* Okay, and your name is? *Pig* Mr. Pig *GN* Okay Mr. Pig, I will send my best men for you! *Pig* \(^o^)/