Well, if the majority of poor people are blacks (and Latinos), then it certainly is a racist policy to have vastly different sentencing for the drugs for poor and rich people.
The question is purely price, and it's the system targeting drug users of certain class/ethnic groups more than others. If you look at drug law enforcement in the US, it's substantially more punitive towards poor/minority groups.
Citation A: https://www.vera.org/publications/for-the-record-public-heal...
Citation B: http://www.drugpolicy.org/issues/race-and-drug-war
Citation C: https://www.aclu.org/files/FilesPDFs/ACF4F34.pdf
Citation D: https://www.forbes.com/sites/erikkain/2011/06/28/the-war-on-...
I can do a the standard English alphabet, the Greek alphabet, simplified Chinese, Japanese kanji and any other alphabets you guys would like me to tack on with sources that state the same thing:
The War On Drugs is a War on Poor People and Minorities.
For example, if crack-cocaine carries a high sentence, then why not drop the habit in exchange for powdered cocaine?
If the question is price, then this is really more of a system targeting the poor than one that is against any specific minority group.