Schizophrenia and Substance Abuse?

I’m writing a book about a schizophrenic substance abuser (there is much more to it than that, don’t worry lol) but I was wondering if anyone had any personal experiences with someone severely schizophrenic, how to they act/talk/etc. I am pretty well educated on the matter but personal experience is much better than facts.
Also; street drugs and prices? that I am not so educated on… lol. I know the affects from growing up around druggies/junkies/alcoholics but since I have been around the users and not the dealers I don’t know so much on prices, just affects…
Don’t worry I will not plagiarize I’m just trying to make sure my writing makes sense to those who might know better than I.
don’t need treatment ideas, just info. read the whole thing ;]