I found this on erowid:

[From 48th edition Physicians Desk Reference]

Equianalgesic Dose (mg)
Name IM PO
-------------------------------------------------------------------------
morphine 10 60
hydromorphone (Dilaudid) 1.5 7.5
methadone (Dolophine) 10 20
oxycodone (Percocet) 15 30
levorphanol (Dromoran) 2 4
oxymorphone (Numorphan) 1 10 (PR)
heroin 5 60
meperidine (Demerol) 75 --
codeine 130 200
-------------------------------------------------------------------------
Note: All IM and PO doses in this chart are considered equivalent to 10 mg of IM morphine in analgesic effect. IM denotes intramuscular, PO oral, and PR rectal.

Sorry, I don't know how to straighten up this table. Anyway, it's a start. now if I can find out how much heroin costs, I'll have one of my answers.