Houston, Texas.
Weed:
$30-50 an ounce of schwag. $20 a gram of dank.
Cocaine:
$30-40 a gram. $80-120 a ball (I generally pay $100). In terms of quality, well, you usually get what you pay for.
Heroin:
$100-160 a gram. Very good quality tar.
Meth:
$100 a gram, usually. Shards.
Ecstasy:
$8-15 a tab. Again, you usually get what you pay for (of course, that's not always true, I've just noticed that generally the cheap ass $8 ones are often meth bombs and whatnot, while the more expensive ones seem more "reliable").
Ketamine:
$100 a gram (yes, completely ridiculous). Sealed vials of liquid.
GHB:
$10 a "hit" of liquid. I suppose that's around 2-3 grams.
Mushrooms:
Potent lab-grown - $10-15 a gram. 1/4 ounce for $60.
Field-picked - never bought any, I got a few friends who like to go mushroom hunting every once in a while, but I imagine they're much cheaper.
Acid:
$5-15 a hit. I usually pay $10. Good quality.
Research chemicals:
Generally $10-20 a dose (last time I bought any, it was some 2C-T-2, $1/mg).
Hydrocodone:
$2-4 for the 10mg ones. Prices have skyrocketed the past few months.
Oxycodone:
$15 for 40mg OC. $50 for 80mg. (Different sources)
Xanax:
$2-3 for 2mg (prices have also gone up lately. 2 dollars used to be commonplace, but nowadays it's usually $2.50-3...).
Soma:
$1-1.5 for 350mg.
Morphine:
Once bought a vial of liquid containing 600mg, for $80.
I'm probably forgetting a few things.