Yes it is expensive!
I have leased a hangar mid-field next to Aurora Aviation for the last 8 years or so and pay $500 a month. It is a larger T hangar with a leaky metal sliding door, poor lighting and the roof leaks too.
At times I have had my S-2B and S-1T and a subleasor's Extra 300 in there so it is definitely bigger than your standard T. There are some nicer T hangars in the same group of hangars that still have the crappy door but have better lighting, sheetrocked (vs. unfinished) walls and painted floors and they go for about $650 a month.
The last hangar I saw for sale at Aurora was a 60x60 for $365,000. Unlike most airports, the hangar owner also owns the land the hangar is on vs. a long term lease which makes them more valuable and therefore more expensive to lease. Before the economy tanked all the hangar owners were trying to attract the biz jet business. Now there are empty biz jet hangars that remain empty because no RV owner is going to pay the $2,500 a month the owner is asking.
It's a great airport though, I love it there!