Pirates also had a lot of star power in its cast along with a massive budget and the limitless marketing muscle of Disney. Unless you're basing a movie's potential success solely on an established fiction, "starting with less" is a bit of a misnomer.
I think you're forgetting that
Pirates of the Caribbean wasn't expected to be the runaway success it was. Remember the last Disney attraction made into a movie before
Pirates?
The Country Bears. Yeah. Making movies based on Disney attractions was no sure thing. Pre-release press expected
Pirates to flop.
It did have a $140 million budget and it was produced by the Disney juggernaut, but it was considered for straight-to-video treatment a few years earlier. As far as the star power goes, Johnny Depp is a wonderful actor, but he's not exactly a reliable draw, in part, because he works on quirky projects, many of which may appeal to him... and not that many other people. Orlando Bloom was buzzing thanks to Lord of the Rings but did that translate into leading man draw? Hard to say. Kiera Knightly had made
Bend it Like Beckham but her big draw years would come after
Pirates of the Caribbean.
Now compare it to its contemporary movie,
Haunted Mansion, which had a $90 million budget, star power that was probably more bankable than Johnny Depp in Eddie Murphy, the same Disney marketing juggernaut, and based on another well-loved Disney ride. Why did
Pirates do so well while
Haunted Mansion did not?
It didn't suck. It not only didn't suck, it was unexpectedly fantastic. The story was fun and exciting. The acting was fun to watch, from the earnest Will Turner, to the warped Jack Sparrow and Hector Barbossa, down to the memorable Pintel and Ragetti. Unfortunately, trying to capture the same thing with any other movie is a bit like catching lightning. Everybody wants to do so, but only a small portion will succeed. It's hard to rely on doing so - but there are ways to make it more likely - none of which, I think, depend on marketing muscle, well-known star power (as opposed to passionate ability whether from a well-known star or not), or a massive budget.