Imagine a familiar scenario.
It is 3:30 on a Saturday morning and you don't really know where you are. The last clear memory you have is thinking that the hot blonde you'd been flirting with was really into your shit, before suddenly realizing you'd actually been talking to a potted house plant for 40 minutes. At some point in the evening you'd been engaged in a melee, possibly with the same house plant. You're standing in a bath tub, but it appears to be located in an alley, not a bathroom. Through the haze of inebriation you remember that bathtubs belong in bathrooms, not alleys. You throw up in it anyway.
Stepping gingerly over a hobo, you emerge from the alley to discover that you still don't really know where you are. You may not even be in the same city anymore. What you do know is that things and stuff are getting clearer and more acute. This is a sure sign that you are sobering up, and may become dangerously lucid at any moment.
Rifling through your pockets you discover an empty cigarette pack, three tickets to see the Bangles (dated October 2005), two drivers licenses from different states with different names featuring the same mug shot photo of a clown in makeup wearing a tiny Pittsburgh Pirates helmet on top of his giant red afro, and $6.78 in wadded bills and loose change. You remember that you hate clowns. You think you can get back to deliciously numb drunk with that much money, but you're not sure.
Fortunately for you, and drunks everywhere, we have the Bodine Value. Named after that esteemed pioneer of the booze industry, Jethro Bodine, the Bodine Value is a quick way to scientifically determine the usefulness of a given alcoholic beverage by leveraging the powerful forces of Math. The Bodine Value is equivalent to 1ml of alcohol per dollar and can be simply calculated using the following formula; (vol * %) / cost. Note that the formula uses the percentage of alcohol by volume, not the proof; don't confuse the two. In the US, the proof number is twice the alcohol content by volume at a temperature of 60 degrees Fahrenheit. US Federal Regulations (CFR 27 5.37) requires labels to state the percentage of alcohol by volume so it should be easy to determine, unless you're already really messed up. If you can't find the ABV value on the label though, simply reduce the proof number in half and move the decimal point two places to the left. 80 proof is therefore .40 ABV. Unless you're standing in boiling water. If you are standing in boiling water, get to a liquor store, quickly.
For example, a 750ml bottle of 80 proof alcohol that costs $15 yields 20 BV. (750 * .40) / 15.00 = 20. Lengthy and very detailed research has revealed that Bodine Values can vary tremendously, and often times present choices that would otherwise be... undesirable. High ABV content liquor, for instance Bookers Bourbon, would seem to offer a high Bodine Value given it is typically bottled around 125 proof (62.5 ABV). However, given the relatively high cost per bottle of Bookers, we find that the adverse is true. The market price for Bookers is around $60 a bottle rendering an average BV of around 7.5, which as you can clearly see is almost effete. Our previous example rendered a BV of 20, which is a very acceptable Bodine Value and in most instances will serve the contemporary drunk well; if you have $15.
You'll note that our hero the imaginary drunk, you, only has $6.78. (Don't look at me like that, you know you've accidentally flirted with a house plant before. I'd bet more than one of you has accidentally sodomized a ficus, and liked it enough to try it again.) In most markets, $5 will get you a 750ml bottle of Thunderbird. At 18% ABV that yields a very respectable 27 BV. That's the kind of math that will get you through the night.
Unfortunately, you may have already realized the single caveat of the Bodine Value. Those beverages with the highest potential value, are almost always the least desirable from a perspective of flavor and not going blind. Thunderbird, for instance, tends to taste like a dead Welsh fisherman vomited up your nose, and leaves you with a hang over that might convince you hobbits with trench foot had spent the night making sweet man love beneath your skull. Remember that the Bodine Value, despite its roots in the sciences, is not a hard and fast rule, but a guideline that serves the drinker on a mission who's been forced to party on a limited budget.
As an aside, it should be noted, that all free booze has an infinite BV, and is therefore the most desirable.