note to SP...it isn't the state who is obtaining the ROI on this.  Its the energy sector that does...and the energy sector is not representative of the country as a whole. 

FYI

The oil market is not your local wholesaler where quantity determines the price. It is not like if you buy over say 1 million barrels you get a 20% discount. It is a spot market where price is the factor that clears orders. Say for example on actor orders 100 million barrels at 90usd and another offers 20 million barrels at say 92usd. If there are no other actors there is no transaction and the market closes as the last transaction price. If for example one actor steps in and buys 2 million barrels at 92usd then you have a transaction and the price becomes 92usd. If there is someone who sells 1 barrel at 90usd then the first order at 90usd gets to buy that single barrell.

So your scenario of US buying in bulk and then reselling in smaller lots at profit is just not possible in the oil market.

First of all prices are not "negotiated" in market transactions. The price is a function of supply and demand at any given price point. ie. if no one is selling at x, the price the buyer is willing to sell, and no one is buying at y, the price where the buyers are willing to sell (x<y) then there is no "price".  Traders and brokers are the middlemen through which buyers and sellers inform the market of quantities at a certain price level (to be baught or sold).

Second PANAMX is very small, it would make more sense to buy and transport in supertanker (ULCC and V plus) lots. The spread in any given stable trading day would be bout 30-50 cents (those points are cents). By the way commodity traders buy and sell to gain from market movements and price variations.

The USD used in the oil trade eventually end up in the US. What happens for most part is that the US buys goods and services from everyone else and pays USD for those. People who obtain USD through trade with the US purchase energy (oil and gas) from producers (mostly OPEC and Russia). In turn Russia and OPEC nations have national surpluses that they usually invest in the US economy or use those USD to purchase goods and services from other nations who in turn once again use that money to purchase energy (and other goods and services). Hence a rise in the price of oil drives up the demand for USD, since that is the currency of energy trade. The fact that the supply of USD is almost infinite (thanks to US trade deficit) means that everyone somehow obrains the USD they need for the oil they want.

If somehow the USD supply became scarce then you'd have the makings of a global recession. That is why the fed is constantly lowering interest rates. It does not want the USD in circulation abroad to come back to the US. The oil producers are happy enough with the situation because the depreciation of the US is far lower than the increase in price of oil. For barrell for barrel they get more Euros or Yens or whatever despite the depreciation in the US. At the end of the day everyone is happy.....

Today's a good example that you're wrong by the way - the most recent settlement and the last averaged price of Oil are in difference of $2 dollars/barrel.

That allows for savings of billions over a year if you're pushing as large of demands as the US.

Yeah I'm using bulk freighter descriptions for size classifications because I'm more familiar with those and DWTs than with m3 etc.

So far your understanding of markets bodes ill will toward any future in financial industries but Management and Organization is one of the largest Bullshill degrees I can think of - you get the same education being a combat officer with 1 tour under your belt.  No offense...it does pay well - and I see nothing wrong with going where the money is...

Oil Prices depends more on future trading (buying in advance - a purely speculative play) than material supply and demand. If you read closely the financial press it reads: "oil ended the day sharply hihger due to worries about limited supply and rising demand" not due to the supply and demand, but due to the worries.
That's ahuge difference because all the oil is bought increasingly longer advance at incresingly high prices.
Oil price doubled in one year. The real demand increased by some 10% globaly (-1.7% in the US!). Obviousely it's market speculation which move oilprices that high.

Just like gold. Poeple don't wear more jewels than before but its price rose 60%.