I'm new to this board (just discovered it today), but hope my neophyte status won't invalidate my opinion!
A little bit about me: I'm African American and both of my parents are working class (neither attended college). I attended a high school in coastal Georgia where more than 70% of the student body received free lunch. The academic experience was not particularly rigorous and the average SAT score was in the 800s (less than 50% of the senior class attended college). I have never had stellar performances on standardized tests, but scored slightly above the 25th percentile for the college I attended (a top 10 university). Despite being admitted with a "low" SAT score, I was one of two African American students who graduated magna cum laude
in my class. I consider myself a prime example of why affirmative action policies are necessary (ie, I was a "borderline" candidate and probably would not have been admitted in the general applicant pool if I wasn't an URM) and good.
My personal experience with Kaplan and the PowerScore Weekend Course validates your hypothesis; namely, if I didn't have the financial resources to enroll in the courses, I don't think I would have been able to intuit the strategies that I learned and applied to increase my score (+10-13 point improvements from baseline). In retrospect, I wish my parents had the financial resources for me to have taken a prep course when I was applying to college; a higher score probably would have made me eligible for additional scholarship opportunities and less undergraduate debt!
I'm five years removed from college and currently work full-time. My industry is very fast-paced and requires long hours and frequent travel. I attribute the improvements in my LSAT score to the fact that I was introduced to the principles of the exam in a classroom setting (I have an equally audio/visual learning style, so am able to retain information better if it's reinforced to me by another person rather than reading it alone) and, more importantly, the timed practice tests that simulate the actual test-taking environment in a way I cannot recreate at home. I attended several sessions with other classes solely to take additional practice tests, and it wasn't until the sixth or seventh test that I started seeing incremental improvements in my score.
I think any reasonably intelligent person, given enough time, could perform well on the LSAT. Unfortunately, the test is not designed to measure basic intelligence and unless/until admissions criteria are altered dramatically, we are all required to fulfill this requirement for admission. Although my LSAT score is unlikely to be in the median for the schools I'm applying to, I nonetheless feel confident that I will score well enough to be admitted to some very competitive programs (what you guys call T14 schools?). I regret that the cost of commericial prep courses may be prohibitive to financially disadvantaged students (minority or otherwise), and that the financial aid that is available is extremely restrictive and limited. It's something that we as future African American lawyers who have benefited from these courses should remember and, if we have the means, subsidize in the future.