Average Keg beer prices

In the United States, most kegs come in ½ barrels between 14 and 16 gallons, ¼ barrels (between 7 and 8 gallons, and 1/6 barrels between 5 and 6 gallons. Heineken also offers a mini keg of beer containing 5 liters that typically costs around $19.99. Found in the beer section of a grocery store, this keg does not require a deposit.
The average cost for a keg is $85 and serves 165 glasses of beer. In comparison, the average 6-pack of beer costs around $6 to $8 dollars. However, the brand and type of beer will also affect the price of a keg. For example, domestic beer kegs generally cost less than micro-brewed beer in a keg. In addition to the price of a keg, a deposit is often required that ranges from as little as around $25 up to $100 or more.
A sample of ½ keg prices from a beer and party warehouse show the differences in cost [1]:

Domestic Beer
Pabst Light – $54.99
Keystone Light – $60.99
Rolling Rock – $80.99
Bud Light – $86.99

Imported Beer
Labatts Blue – $91.99
Molsen Canadian – $91.99

Micro Beers
Saranac Pale Ale – $85.99
Blue Moon Belgium White – $125.99
Sam Adams – $133.99
Sources:
[1] http://www.savemorbeer.com/products_beer_kegs.htm