Value is so subjective. I honestly collect based solely on eye appeal. If there is a marble out in the wild or hidden in a lot on ebay that attracts my attention and it happens to be worth $400, then that's amazing of course. But I like what I like. There are some very expensive marbles I don't find appealing at all and don't collect (at least not at this point). It's really all about what YOU like.
To be completely honest, there are some imperials in that last photo that I personally like, but many would consider "junk".