Signed BTS album for low money?

Hello, i’ve been a BTS fan for the past seven years and I am currently in the process of trying to grow my album collection.

I recently came across a Facebook post on Facebook marketplace. The person is advertising and selling off all of their BTS albums, one of them is signed. I immediately thought that I should put in an offer for it. I’ve been unlucky and I’ve never been able to get anything signed however the album is going for an extremely low price.

Is it normal for BTS albums that are signed to go for low prices genuinely asking because I thought that signed BTS albums go for a lot more money and they are only asking $40 for it.

Please help! I don’t want to get scammed!