Santiago is a smooth-talking con artist living in Freeside. He affects a Spanish accent to get out of paying for drinks. Thanks to his dishonest ways, he owes Francine Garret 212 caps and has no intention of paying them back before being confronted by the Courier in the side quest Debt Collector.
After Wang Dang Atomic Tango has been completed, the Courier can have sex with him for 25 caps.
There is a dialog option where the Courier can ask for a discount to Mick & Ralph's for 50 caps (25 caps with a speech check). He will instruct one to tell Mick or Ralph the word "extravaganza". When this is done, however, they will tell the Courier that he or she has been set up since Mick and Ralph's doesn't do discounts. There will be no dialogue option to talk about this once the Courier returns to Santiago. However, the option will appear when the Courier comes to recruit him for the Garret twins.
Intimidating him will cause him to pay the Courier 256 caps.
If the Courier kills Santiago, they will find 25 caps on his body and they will neither gain bad Karma nor infamy in Freeside even after finishing Wang Dang Atomic Tango.
pcps3 Recruiting Old Ben to satisfy the "Suave Talker" requirement of the quest Wang Dang Atomic Tango will make it impossible to collect the debt from Santiago through dialogue. Attempting to collect the debt will simply result in a selection of dialogue options where the Courier has no choice but to pay Santiago for his bogus discount password to Mick & Ralph's. [verified]
(Solved via patch on 360 and PC)
The option to recruit him for the Garret twins' prostitution ring is available upon meeting him if the quest Wang Dang Atomic Tango has been accepted. This will inadvertently accept and accomplish the initial quests of Debt Collector up to the fine-paying, and all options to pay the fine, except out of pocket are gone. This also will screw up your interactions with Francine Garret and possibly prevent the Courier from completing the quest. You can pickpocket a "bag of bottlecaps" off of him to fix this bug. [platforms tag needed]
If you have already collected Santiago's debt and are tasked to kill McCaffery in Wang Dang Atomic Tango, you will receive the previous quest "collect 212 caps from Santiago in Freeside" again. If you kill Santiago, the 212 caps are not on his body and there is no other way to collect the caps from him. [platforms tag needed]