Broadway shows or Broadway traveling shows are expensive and have been for decades, no doubt about that. That means we are really choosey about what we go see and don't see that many shows. A really good show, though, is one of my very favorite splurges (so uplifting), just like a fun theme part day is a splurge for me (so much fun).
I would NOT buy resale tickets (you really pay a premium). Buy from the official website for what is still an expensive ticket, but is a fair price. At the Fox theatre here in St. Louis (I am not a season ticket holder), I sign up for their mailing list and that let's me buy tickets a week or so before they go on sale to the general public. It lets me get a little better seats or an earlier choice for seats in a particular section.
The Lion King show is really good -- interesting costumes -- opera inspired. These are just my thoughts though, IMHO the story is so much like the animated movie, no new ground here so it's an expensive add on experience. I prefer Broadway shows that cover new ground, aren't based on a movie. My two favorite Broadway shows are "Les Miserable" and "Come From Away". Now Lion King is a great first show if you are wanting to take a child to see their first Broadway show and yes go if you really want to see it, see what all the hype is all about. But I would say skip it if you are balking at the prices and aren't in either of those other two categories. - just watch the movie and if you are at Animal Kingdom go see the little mini show, Festival of the Lion King, that is so much fun. The Broadway show FYI is the highest grossing Broadway show of all time -- has had staying power and mass appeal. My aunt was a HUGE fan of this show. She is deceased now, but OMG she went to see it with her husband five times. It really appeals to some people big time.
My son is a HUGE fan too. We took my son when he was six. He loved it, went again at 12 (really wanted to go so we caved and took him), went again at 18 (yes we caved and took him again when it was in our town), and then he went to see it again at age 25 when he was in New York. This and Wicked are his two favorite Broadway shows and the two shows he could see over and over. I have more of a one and done personality on things like this, as good as they are.
It was cute at six, DS didn't realize what a splurge it was to see Lion King and said "Mommy this was so good. Can we come back and see it again tomorrow?". I had to explain that these were really expensive tickets and that this was a special splurge, not something you do every day.