Oxy/Roxy is expensive and once you can't afford that anymore then you just go to heroin which is way cheaper.
Also when scripts end, people often go to heroin. A lot of veterans especially.
This is highly accurate. Pill biz is booming in the streets. Roxy's are slang for Oxycodone. A 30mg Roxy sells for around 18-20 a pill. Hydrocodone 10mg are going for around $8. 5 years ago they were $5. When people can't afford their 8 hydrocodone pill habit of $64/day they buy heroin which is much cheaper.