Richiev's version, while it encapsulates the concept nicely, also highlights the disjunctive logic that makes the concept a head scratcher.
A logline is a statement of a plot with a cause and effect relationship between the inciting incident and action that follows. So words like "after" and "when" in the inciting incident clause could be replaced by the word "because". So:
Because he?s scammed out of his life savings, a beloved but over-trusting school councilor, travels to Nigeria to prove the Nigerian prince does exist and there?s still honesty in the world.
How logical is that?
What the logline really says is: "IN SPITE OF being scammed out of his life savings..." IN SPITE OF past scams and cons, the school counselor remains an incurable naive fool. So what's the character arc? If he gets the inheritance, then what has he learned, how has he changed? Well, he doesn't have to change, doesn't have to grow as a character to get the inheritance. He just has to persist with his defining character trait -- continue to play the naive fool.
Will it play? Well, didn't it play as a running joke for Inspector Clouseau in the Pink Panther franchise? And isn't the Fool Triumphant a standard and beloved comedy trope?
Maybe it will work again with this story as a mashup: Professor Clouseau meets the Nigerian scam artist. I suggest that the joke is that the counselor is truly being conned again, has fallen hook, line and sinker for a Nigerian scam --but this time, like Clouseau, his folly manages to outwit the cleverness of the scam artist, the "Beautiful Prince".
Good luck and best wishes with your concept.