[While this is not a discussion of Breaking Bad's plot, there are some spoilers. So, if you haven't gotten into the most critically-acclaimed show on TV yet, consider bookmarking this and firing up Netflix right now.]
So, without further ado:
In season 5 Walt and Jesse cook "nearly" 50 pounds of meth (let's say 45), which brings them $1,379,560 in gross profit, or their revenue minus the cost of the raw materials. The time period over which this money was made is not told explicitly, but we will assume this was one week for reasons explained later. So, all the numbers given for a week will be multiplied by 48 (assuming 4 weeks vacation pay. Cooking is hard work) to show yearly amounts.
Mike takes a big chunk of the income for expenses only required due to the illegality of the business (legal meth would eliminate these costs, but also drive down the price with competition, taxes and regulations); the biggest piece was nearly 25% in "legacy costs", or paying off the families of the 9 men in jail from the last operation. Walt's anger in paying for this was in one sense justified; the last operation was a separate business and shouldn't appear on their balance sheet unless there was a kind of chapter 11 bankruptcy that made this operation a successor to the last one. However, (SPOILER) since Walt killed Gus, and is the reason this operation failed and the men imprisoned, we'll just call this a necessary business expense.
** Mike informs Walter that methlymine, their most important and difficult-to-legally-obtain ingredient, will become an ongoing expense even though the first shipment was free. The cost (and effect on the business) is not brought up, but I can figure this out. 1 gallon, according to the infinite wisdom of the internet, could make 74 pounds of meth, so MethCo would need ~30 gallons of methylamine to last a year making 45 pounds a week. With 1000 gallons of methylamine going for ~$15M on the black market (as evidenced by the proposed sale in season 5's "Buyout"), this would set the 3 not-so-amigos back a half a million, easily a million after the cost of safely obtaining and moving it.
So, MethCo would earn $18.5 million on sales in the 70 millions. Walt's right that he can support a NASDAQ-sized enterprise, but MethCo is hardly Apple. His business's sales would rank below thousands of publicly traded companies, among such heavy hitters as StealthGas, Inc (74M in gross profits) and PetsMed Express (77M in gross profits). The business's income is a little better, around the 40th percentile of NASDAQ-listed companies, but there are CEOs of much larger companies that manage to not become egomaniacs. Regarding margins, Walt's 20% (higher if he can scale production to send to, say, the Czech Republic) is more impressive, similar to mature cash cows like IBM, Google, and the company to which Walt compares his product: Coca-cola (21% PM in 2012).
Walt's high sense of self-worth stems in part from the fact that he is not only the primary decision maker in his empire, but also the 1/3 (and later primary) owner. Working at Google is no reason to do doughnuts in a parking lot and then sell your car for $50, but owning a third of Google probably would be.
Investors would not pay that much for a piece of Walt's drug empire. It is far riskier, has more dangerous management, and is less likely to be around in a year than virtually any publicly-traded company, but is performing better than only half of them, depending on what metric you use.
But as Walt has himself confirmed, money is not the primary motivation for his cooking meth. The industry in which Walt has involved himself is perfect to satisfy a dormant over-sized ego. There is little competition and even less competent and intelligent competition, intimidation is the currency of all interactions, and staying above the law relies on detachment from others and a cold, single-minded focus on expansion. Walt provokes conflict with Mike in the scene I discussed not because he needs more money, but because he must preserve his feeling as the ultimate decision maker, and the smartest man in the room. He's in the empire business.
Is my view of the empire unjustified? Is my math awful? I'd appreciate your thoughts!