There is ZERO chance Tony would have killed Artie over $50K, and I'm certain that was the last thing on Artie's mind. Tony
pisses fifty grand. The suicide attempt wasn't about money. It was about being a failure. He was going through a divorce, so he's a failure as a husband. He couldn't afford braces for his daughter, so he's a failure as a father.
His restaurant isn't doing well and Jean-Philippe just screwed him over in a "business deal," so he's a failure as a provider. His lame attempts to make Jean-Philippe's sister fall for him were unsuccessful, so he's a failure as a ladies man. He can neither intimidate nor beat up a 120-lb. French guy, so he's a failure as a tough guy. He can't pay Tony back, so he's a failure as a friend. (Note Artie's frantic phone call to Tony after he took the pills: "I'm sorry I let you down.")
He is despondent. Nothing is going right in his life. So he's going to kill himself because he's afraid of being killed??