It will cost you 66,100 Energy (and V$510,000) to complete the Energy Path of District 8 in Las Vegas... but only if you insist on doing it the hard way.
Even for the mightiest of energy accounts, this is a tall order. But if you get some help from your Mafia, you can cut the Energy cost down from 66,100 to 35,900 - still a tall order, but 45% less energy than you'd otherwise need.
The District 8 Energy Path has 5 jobs. One is a Social job, which gives you 1% completion per click. The other 4 jobs give you 2% completion each time - one of which requires you to PAY V$10,200 each time for the pleasure.
And doing each job ONCE requires between 136 and 194 energy. Plus two of the jobs require Vegas consumables: Alarm Codes and Hot Tips, which set you back 79 and 108 energy APIECE.
Break out the calculator and you'll see that doing the Social Job 100 times, and the other four jobs 50 times, plus the costs of consumables, requires 66,100 in Energy. Ouch.
They key here is NOT to do the Social job at all. Instead, click on the Ask Friends for Help. The Social Job - Discover a Big Meth Buy at the Hoover Dam - will cost you 30,200 in Energy to complete by yourself - because you need to do it 100x and you need a Hot Tip each time you do the job.
Each time a friend helps you on this Social Job, you get 10% mastery. That's right - with one click, it's like a friend saving you 3,020 in Energy (that's the equivalent of 10 Hot Tips and doing a 194-energy job 10x). So when you see YOUR Mafia members posting Social Jobs on their news feeds, HELP OUT!
Also, with the 2x Mastery feature floating around, you can complete the Energy Path for less than 35,900 Energy... earning you a fourth and final shot at Governor Halloran, the District 8 Boss...