The price definitely fluctuates depending on the quality.But there is a ball park range for each quantity you are asking.
Q: How much does marijuana cost per gram, eight and ounce in Illinois.
per gram it can cost anywhere between (10-20 dollars)
per eight it can cost anywhere between (20-60 dollars)
per ounce it it can cost anywhere between (200-350 dollars)
The price of quality marijuana in Illinois ranks among the highest in the United States with $20 per gram, $60 per eighth and around $350 to $400 per ounce. It would cost you an average of $350.29/ounce for high quality dope; $287.86 for mid-grade and $203.61 for the cheap stuff.
In 2015 studies showed that medical marijuana dispensaries were charging about $16 per gram making it about $56 per eighth. An ounce of medical marijuana was selling for about $450. The cost for marijuana was much less on the streets however not legal. According to CBS local, in 2016 it showed that the price for medical marijuana had dropped to around $350 per ounce but it was still less in Indiana.