I live in the city of Alameda, which is an island in San Francisco Bay, right next to Oakland. A while ago, when I pulled off the freeway in Oakland on my way home, I saw a truck in front of me for an auto stereo installer with a sign that read:
"If it's too loud...
You're too old"
Not to say that hip-hop wouldn't sound good on a hi-end system, but the point of a high-end system is detail, clarity and imaging. It strikes me that the most desired qualities in a system for hip-hop would be the ability to produce high sound levels of deep bass, good dynamics on the high end and mid-range clarity. I don't think the kinds of natural detail you look for in chamber music are of much importance in high-level hip-hop.
While it's always nice to look at some $35,000+ hi-end loudspeakers, most younger listeners (and I assume that hip-hop listeners are younger) aren't going to have that kind of loot to drop on loudspeakers. The kind of speaker that many of us would want for listening to jazz, classical, or even bluegrass music, at the $2000 price point, wouldn't be able to put out high sound levels of deep bass, let alone do so for an extended period of time.
But at $2000/pair, it would be easy for a hip-hop fan to acquire some good PA speakers that would keep him/her happy. Now before y'all audiophiles have a cow, I want to qualify this statement. I'm all about value for your limited audio dollar. At the lower end of the price spectrum, I feel that PA speakers will provide a better value for music that calls for high sound levels and not particularly cares much about the natural tonal qualities of acoustic instruments. Hip-hop and a lot of rock fall into that category.
If you look on Craigslist, you can readily find bands selling PA speakers with 15" bass drivers (there's no replacement for displacement), horn mids and highs, capable of high sound levels for very little wattage. For a hip-hop fan, I think $1200 on some decent PA speakers will be a much better value than some used mini-monitor better suited to chamber music.