It's an interesting question. Kyle, you and I might have some shared experiences in such matters. They really suck is about the long and the short of it.
That said, I am going to disagree with you for the following reasons which are in no particular order:
1. There are already laws against possession with intent to sell. We could argue that the seller (drug dealer) who uses too much rat poison to cut the heroin in misrepresenting the final product and hit him up for fraud but really, what's the point? I have seen nothing to make me believe that heaping laws upon laws and adding new laws to broken laws trying to fix them does little but keep lawyers in business.
2. Adding onto crimes that are already illegal does nothing to address the problems in the criminal justice system, namely, prosecutors adding to charges to get a decent prison sentence and prisoners getting out of jail because of overcrowding, parole, good behavior, you get the idea. How about a system where 30 years means 30 years?
3. The addict bears responsibility. If I drink vodka until my liver pops there is one person at fault. Same deal if I snort cocaine until my nose falls off. Same deal if I smoke bath salts and bite your nose off. My use, my responsibility. I say this as an addict who has been clean for almost seven years.
4. Drug dealers are the scum of the earth and should be treated accordingly, specially those that breed on kids and use kids as mules. My personal feeling is that they should be, at the very least, waterboarded until they give up the names of those on the next rung up the supply chain.