Most folks who use LSD only do so occasionally; stop entirely after the first few times.

The difficulity of manufacture has little to do with lack of supply - heroin, cocaine, etc aren't exactly easy to manufacture easier.

Ultimately, it's all comes down to basic economic rules of supply and demand ... there's little demand for LSD compared to other psychotropics and thus LSD remains scarce and pricey.

Rat poison in LSD is a myth ... adding strychnine would likely increase the cost of manufacture; wouldn't matter even if it was in there anyways, since the amount would be so tiny as to have little to no effect.

While on myths ... LSD does not remain in the spine nor anywhere else; according to my understanding, most of all LSD consumed is metabolized within about 20 minutes - the long lasting effects of LSD are thought to be from imbalances in brain chemistry that continue long afterwords - typical LSD trip is around 16 hours or so.

For more information on LSD ...

http://www.drugabusehelp.com/drugs/lsd/

Ron