Well, there is no difference to me between ‘‘fiddy’’ and '‘fi’tee.’ They sound exactly the same to my ear. That’s because the word ‘‘fifty,’’ when I say it going about my normal lily white business, isn’t pronounced with a hard ‘‘t’’… it sounds life fifdee. So AFAIC you’ve got ‘‘fiddy’’ and ‘‘fi’dee’’ because that’s how I talk.
Am I the only one who doesn’t pronounce ‘‘fifty’’ with a hard ‘‘t’’? I grew up in the Midwest.
“Fi’tee” or “Fiddy.” My understanding is that that is how Curtis Jackson’s stage name is meant to be pronounced, and so that is how I pronounce it.
“Fi’tee” is not an accent, it’s a specific way of saying a deliberately chosen stage name.
Here…have some budder. We godda get tuhgether layder, donyou think? 
Yep, it’s a Midwest thing, and in this case, Chicagoland *is *part of the Midwest.
Then there’s the new rap sensation Ask Me.
“Axe Me”
It’s rapper slang, and white people love them some rapper slang. Eerbody in da club knows that.
I doubt that most white people think that every black person is incapable of saying “fifty.” It is fun to say “fiddy” every once in a while. Also, it’s fun to say “eerbody” and “get your nails did” and all the other stupid little bits of slang that white people have stolen from black people and made uncool.
/white guy
I agree with all of this, but due to the wonders of the internet, I have found it can be a minefield, even with my own name. I have noticed that there are a couple different pronunciations of Sarah, the way we pronounce it here in the midwest “SARE-uh,” and the more east-coast/British pronunciation “SAH-ruh.” I have always my whole life figured this was an accent thing, and I have been called both.
Come to find out, some people are much more particular than I am about how it’s pronounced, more like an ANNdrea/OHNdrea thing, and they get butthurt if it’s not said “correctly.” ALSO that it is somehow tied into the spelling for some people, that with an H it’s one pronunciation, and without the H it’s the other.
Damned if I knew any of this.
Regarding Fifty Cent, I always called him Fiddy, based on what I hear in the media, but I’d never heard him say it before. I always figured he did it as a stylized thing, because while I do think Black folks pronounce it differently from white folks, I don’t think “Fiddy” is a good representation of that accent. Anyway, I just listed to that clip, and to my ear, he is absolutely not saying Fiddy…I can totally hear the F sound in the middle of the word. I think it’s kind of hilarious now that the Fiddy thing is apparently white person interpretation of the AA accent, just as the OP suspected. Dang. How embarrassing.
That’s only twenny-fi cent.
If I heard that you are really supposed to pronounce it “Fiddy” then I would but I always just assumed it was an accent/dialect thing.
The digression into, “No, I shall call him Fifty Cents because that is grammatically accurate” is cracking my shit up, and reminds me of the Onion article, “William Safire orders two Whoppers Junior at Burger King.”
Da club? You whack, brah. We all in da hizzouse, yo!
(Ok, now I feel dirty. And old. That has to be, like, a decade out of date, right? Even for a lame white version? This is why I embarrass my kids, isn’t it? 
)
Incidentally, what’s grammatically incorrect about “Fifty Cent”? That is a perfectly acceptable adjective.
I think people want Cent to be plural. Which, logically, it ought to be, but I’ll get back to you on that after I put on my pair of pants and place this fifty cent piece in the pocket.
I’ve said fifty, and been made fun of every time for saying it that way.
Are you sure you wish to adopt that as a tagline? 
My husband and I will say “fiddy” for “fifty” at home, not because we think it’s the way anyone, anywhere pronounces it, but simply because it makes our kids crazy. That’s our right and priviledge as parents.
Has anybody heard the expression “solid quarter?” Is that regional?
I say “fiddy” because I think it’s more ridiculous that way.
I also own a Honda Fit.
Her name is “Fiddy”.
I heard it a lot when I worked at a teen dance club with a few arcade games in the early '90s in Harvey, Illinois, always from black boys. Black girls and white boys and girls would just ask for “a quarter”. For obvious reasons, their two-dimes-and-a-nickle were not useful in an arcade game.
Where did “get your nails/hair did” come from, anyway? That’s the one that makes me cringe nails on a blackboard style whenever I hear it.
“Toob its”
Was this covered in a South Park episode? Somewhere I’ve heard “Fitty sent” before but I’ve no idea where, nor did I know it was anyone’s name, rapper or otherwise.
Its called “case quarter” around here.
Wasn’t that Chef’s Dad and that whole deal about “two-fiddy” and the Loch Ness Monster and all that?