How does tipping Moxxi work? [duplicate]

Solution 1:

According to the wiki, Moxi will give you the weapon Bad Touch, a corrosive SMG, after you have given her 10,000-20,000 dollars. The weapon Good Touch, an incendiary SMG, will be given when you have tipped her 20,000-50,000 dollars.
Both weapons may have further additonal randomized values.
These two guns are the only two things Moxi will give you when tipping her.
Considering the amount of money you get from one gun, you can calculate the monetary gain (or loss more likely).
The amount you tip her is also cumulative within the same playthrough.
After Moxi has given you a gun you must leave Sanctuary to be given another reward for tipping her, as continuing to give her money before you revisit the area will only result in you losing money.