Just another few tips to maximize the prize of this achievement.
My suggestion is the have lady killer / black widow perk, 75 points to unlock doors and a very hight conversation skill (or modifiers).
Now: talk to uncle Roe to get more caps (from 200 to 400). If you talk to both superheros and persuades them to leave, you'll get 600 form Roe.
Reach the AntAgonizer's lair if you're male (or Robot Repair Facility if you're female).
You can kill the ants in a row, these are very poor foes. When you reach the hideout, talk to AntAgonizer using lady killer ability, she'll give her armour to you. Take it with you and reach Robot Repair Facility.
Eliminate the robots on your left, then turn right: an elevator is on your left, just around the corner. Force it and you're in the Mechanist's hideout.
SAVE the game. Use any ability you can to win a very hard speach check.
Now talk to this crazy man and try to persuade him to leave the city. Reload if you fail.
When you're done, come back to uncle Roe: you've got 600 caps, the achievement.... and 2 two superheroes suit... very funny: now you can act as superhero *LOL*