Need your advice before buying a Dreamcast from Ebay

[Akeran]

Hello,

I'm not sure it's the right forum category for this, please move it if not.

I'm interested in a Dreamcast Sonic edition (greenish background with some Sonic characters) on eBay and would like your opinion about it.

I've learned that it's a lot better (and personally I would prefer it) if the serial number match the console, the manual and the box. But the seller told me that there is no serial number on the box. Indeed, there is a hole through the box where we can see the serial number on the console inside. But I was wondering if there is another place on the box where this serial number could be seen?
Should we also see this serial number on the manual?

I also would like to know if there is a cardboard in this Sonic version, because on the pictures I see two bottom inserts?

And is there a Demo disc in this version?

Thank you for your help!