There are many factors to take into account when attempting to determine the true cost of owning a kegerator as opposed to buying beer at the store. On the kegerator side, there is the lowered price of the beer, the cost of a slightly increased energy bill to keeping the kegerator running, added cost of CO2 tank refills and beer line cleaners. On the store bought beer side of things, one must consider the hassle of making beer runs, limited store hours, gas expense, the increased price of the beer, the ordeal of picking up used cans and bottles around the house, and shortages of your favorite kind of beer. Of course, beer from a can usually pales in comparison to a glass of draught ale, but let's first look at the bare bones finances.
Just in terms of the price of the actual beer, you are paying roughly $70 for a 15-gallon keg of good quality beer. That comes to 160 12 ounce bottles of beer - 13 and one-third six packs. Considering the mark up at the corner store, most of these six-packs are going to wind up costing you in between $7-$9, including a modest deposit. This means that, on average, the cost of an equal amount of beer, store bought, is about $107. This is the primary point of savings with the use of a kegerator. Even if one bought keg beer for a big party where all was to be drunk in one night, the cost of ice to keep the beer in flowing in good order is likely to be between $12 and $20, plus the rental of a tub to pack the ice in around the keg.
Now, let's look at the cost of just the kegerator itself. There is an initial investment in your kegerator equipment, which may cost between $50-$500, depending on whether you convert an old fridge with a kegerator conversion kit, or buy a fully functioning kegerator new. There is the $5 per month added to your energy bill each month for having a kegerator. Last is about $25 every year for beer line cleaning supplies.
Assuming that one is drinking two six packs a week, the cost of buying that much beer is likely to come to $13 per week. The cost of drinking that many 12-ounce beers from a kegerator is likely to come to about $7-8. So we're talking a savings of $5-$6 per week. Or, $20-$24 per month. Multiply that by 12, and you get between $240 and $288 per year in savings. If you brew your own beer, your savings increase by one-third to one-half! Even the top of the line kegerator is likely to pay for itself within two years, and if you use a kegerator conversion kit, in less than one year!
Financial saving is only the beginning of the story - with the use of a kegerator there is no need to fuss about with cleaning up cans and bottles. No need to taking them back for deposit, or to pay the deposit. There is a deposit that comes with buying kegs of beer, but, honestly, you are far more likely to get a keg deposit back that a bottle or can deposit.
In some senses, the use of a kegerator cannot really be compared with drinking canned or bottled beer. With the kegerator comes a perfectly formed glass of draught beer - something even the widget beers seem to fail in truly achieving perfectly. If you consider the increased cost of widget beers into the equation, the savings becomes astronomical. And for the home brewer, there is no question that the kegerator is a good choice - the only way to enjoy one's own home brew as a draught ale.