Anyone can clone a site with the help softwares and little bit of edits/addition to files here or there to make it a complete working site. There are bunch of softwares which will help you clone but it wouldn't provide you any kind of backend files or files for which public access is disallowed. So I have this hunch that you are selling just a clone and not the whole.
Also other important thing to note that these kind of files could be used to create phising site with same design like bitcoinvideocasino. And who give you permission to sell a clone of the site?
there is no point to even consider buying this as it is like buying a cat in a sack
not only you are not guaranteed that the site will be working
it can be anything, literally anything inside that archive: Xmas carols, funny pictures, random script etc.
do not be retarded and feed this scammer, he is posting different "scripts" for sale under different aliases
hoping that even if one pays him 0.03 btc it is 120$ and well worth his time