When he falls in love with a writer and her amazing script, a con-artist poses as a producer while avoiding the people he swindled to turn the script into a film that will make more than any of his scams.

"...will make more than any of his scams." -- make more what, exactly? Cash?

If he falls in love with her, his next move wouldn't be to scam her, now would it?

The best stories seem to? be between the relationship of the characters. Always know who your main character is so that you can promote the story accordingly.

Here is my version with the con-artist as the M.C.:

A man poses as a producer to con a writer out of her script yet struggles to complete the task after he completely falls in love with her.

btw, this logline isn't far off, I wouldn't make too many changes just small little tweaks. You should get good advice but if you follow all the advise it may actually muddy things a bit.

I like the premise.

I would change the end of the logline though. If he falls in love, the overall goal should not be to make more money than his previous scams.
Maybe his goal should be to prove that he has changed his ways. That he is not the scam artist he used to be.

"When he falls for a brilliant scriptwriter, a notorious con man poses as a producer to get her film made while attempting to outsmart a former mark out to prove to the writer that the con artist is running a scam"