For $500.00 you get first crack at housing. This is huge as all the rooms close to the con sell out fast. Addtionally you get a bag of swag and some exclusive VIG only stuff. I got:
VIG Pin
Gencon 2013 Bag
Gencon Tshirt
Gencon Flask
Mayfair Water Bottle
Badge Holder
Paizo's campaign setting (which I had but I used as a gift)
Settler of Catan Card Game
Copy of Hasbro's new version of the DnD rules
A pack of Yu Gi Oh cards and a mat my 12 year old flipped over.
A fun little dice game called Fandooble
A copy of a card game called Ratuki
We got some odds & ends that were interesting but unremarkable.
There is a VIG mixer on Friday night at Ruth Chris steakhouse. You also have access to the VIG lounge throughout the convention. You are able to muster here, getting your tickets and such in 6 minutes as opposed to 3 hours. Will call at Gencon is butt ugly. They also have a VIG only cooler in here where you can get beverages of the non-alcoholic sort any time you want. You can store loot here by checking your bags. It is a nice, calm and quiet place to hang out and play games, relax or scheme and plan.
You also get early access to the dealer room. You get one hour to beat the rush. We used it to pick up a bunch of stuff that required REALLY LONG LINES later on. We were able to see the entire dealer room as a result.
All in all, this was worth the price. I got $300 worth of Swag, probably drank $50 worth of water and soda and saved myself a ton of hassle by having the VIG lounge to hang out in. The mixer was easily a $50 value. You can have up to 3 VIG companions with you. These tickets are about $75 I think and they get the same access you do but not get swag and gave to pay for the mixer.
My advice: try to get this. The slots sell out in under 5 minutes the day Gencon registration opens, but it is worth it. Once you have "made it." You get first option to renew every year and that is my plan moving forward.