More Claims from Cleveland on the "LeBron Effect"

So this made the rounds yesterday, supposedly providing more evidence of the huge economic "LeBron Effect" in Cleveland:

“@darrenrovell impact on arena debt service payments w LBJ back" Yeah, that LeBron effect all made up @StadiumShadow pic.twitter.com/8DZJU0FTIf
— Ian VanBuskirk (@tampagatoraid) July 22, 2014

I reached out to the incomparable Neil deMause, of Field of Schemes fame, since he is more familiar with Cleveland's financing, and he pointed out a number of possible problems with this message:

1. Like the $500 million LeBron economic impact claim, there is no source to this data. So, who knows if it was just made up like the $500 million LeBron economic impact claim.
2. For LeBron's eight years in Cleveland, the ticket sales tax had five crappy years and three good ones; after he left, three crappy years and one good one. 
3. The Cavs currently sell about $30 million a year in tickets (per Forbes) and the ticket tax is 8%.  So it makes no sense that the chart claims the ticket tax alone is providing $4M-$8M per season in revenue.  Furthermore, 8% of an extra 200,000 tickets per year (at ~$50 a pop) would only seem to generate an additional $800,000 in tax receipts.
4. The arena also hosted non-Cavs events as well, so its impossible to tell from the chart how much of the tax revenue was actually due to basketball games.
5. As for the 2014-2015 and 2015-2016 projections, deMause indicates the asterisk next to the projections likely means "wild-assed guess."

UPDATE NOV 17: Holy Cross economist Victor Matheson joins the chorus debunking the $500 million claim - it's worth a read.  His conclusion: "why accept economic impact studies that are off by at least a factor of 10? Sports fans, not to mention local taxpayers, deserve better."