There was an article in the T&T several days ago pertaining to the cost of parking garage. If I remember correctly, the average price per car stall was around $24,000. And I think that was construction cost. Not including maintenance and operating cost.
Google searching the topic comes up with pretty much the same cost.
If this is the case, then a 300 car stall parking garage would cost $7.2 million.
If you count 140 events per year @ an average 2.5 hour show, and fill all 300 parking spots at a rate of $2.50/hr, that equals to $262,500 per year revenue.
$7.2 million divided by $262,500 equal 27 years.
Let's not count in all the other factors: extra revenue from non event parking, maintenance cost, operation cost, electric bill, property taxes, etc.
So who wants to go into the parking garage business?

Not me!