Looks nothing like the autographs I see for sale from reputable sources. I'm no expert. But it looks so off I'm not sure you need to be an expert. Here is a one on Steiner's website. Upper Deck COA. No question authentic (with the price to match).
It's also on a $15 basketball that you can pick up at Walmart. Typically, indoor outdoor balls are common for autographs of limited value. No sense paying $140 for an authentic leather NBA ball to have signed by a player who's signature has little value.
Labron, however, would be a strange choice to have him sign a very cheap ball, given the value of his signature. I would go with your instincts on this one.
For athletes of LeBron's stature, just save up and buy it from Upper Deck. Same goes with Jordan, Tiger Woods, etc. It's just not worth the risk. These people are incredibly hard to get to, and do not sign very often.
If it seems too good to be true, it is.