Money shouldn't be too hard to come across in this game as it's everywhere. You'll get it from completing main/side missions, killing enemies and completing challenges.
Moxxi can be found in Sanctuary at her bar & club called Moxxxis. You can't miss her, she's behind the front desk. Once you spot her, you'll notice a glass jar on the front desk which has some red lips poking out of it saying, "Insert Your Tips".
Look at it and you'll be prompted to either give Moxxi a $100 tip by pressing or a $1,000 tip by pressing . If you have the cash, press to hand over a $1,000 tip. Now do this 9 more times and the achievement will unlock. If you don't have enough money don't worry. You can come back at any time to give her the remaining money, it does not have to be all in one go.
*If you want to keep your money, simply save the game before you give the full $10,000 tip to Moxxi. Once done, quickly dashboard. Now just load up your previous save and you'll still have your $10,000.
slaughterdome is located in wildlife preservation area and is known as the "natural sepection annex". the term "creature slaughter dome" isnt used.
fyi thiugh, after i gave her 10,000 i got the achievement but then i gave her a few thousand more and was rewarded with a purple legendary Maliwan submachine gun known as "Lucid Bad Touch" lol! has a picture of Moxxi on it too. the legendary text says "when im good, im real good".
considering i just got it at level 30 it scaled to me too so its stats are pretty good. i wonder if i keep giving her more moey if she'll give me another gun?
You CAN get your 10k back! Just tip her the money. Then, xbox guide button, sign out of profile, youll be returned to the main screen (without it saving). Also, you could go to the xbox dashboard. Just DO NOT save and quit!
have a high level friend bring you drops they dont want and sell them (10,000 per item sometimes) i racked up 200,000 in no time and was able to tip her for weapons and use slot machines endlessly for a while
You don't need to tip thousands, i tip her 100 at a time and sometimes i get her gun after 3 or 4 100$ and sometimes it takes 50 100$ to get it. so giving 1000 a shot is pointless once you have the achievement.
i come back to her every 2 or 3 lvl to get a more powerful fire smg each time. btw, her guns vibrate and it is quite distracting so i simply disabled the vibration option in my main xbox menu and now i can finally use her guns normally.
continue giving her more durring the corse of the game she will give you a fire n acid smg that go whit the main quest level n are really strong ps you got to keep giving her in one go till she give you one n stop listening when she talk to not pass the weapon