Questions about Explorer

[mck22]

Ok I just bought my first Submariner about three or four weeks ago and I love it. I found a friend of a friend who is wanting to sell his Explorer to me. He sent me some pics which I will add on here so you experts can take a look at it. He also send me a pic of the top of the paperwork with the serial number and style number. To a new person like me it looks like the real deal, but as we all know buying from a individual and being new to this that can be very dangerous. I am wanting to be cautious. Can someone help me to see if this is a real watch, and explain to me what I can do with the paperwork? Any help or thoughts would be great, I am trying to learn and understand all of these things. Also what is a fair price for something like this? I looked and it seemed to be a mid 01? Is that part correct. Well post what you want to share with me. Thanks guys you are all great.

The paperwork says it is a K267XXX
Style r16570a30b7879