Over here it tends to be a pretty standard �20 quid for an 'eighth' but the actual amount you receive and the quality tends to vary from dealer to dealer. You can get an ounce for about �140-160.
In my area, the prices depend on the strain. The person I buy from sells medical so I get the good shit, which is a little more expensive. I get a gram for 20, and 8th for 60, or a quarter for 120. I have only ever bought an 8th once so I usually spend 20.
As for thunder, there is nothing in the Clraik rules about posting about drugs. I posted a board the other day about how I tried shrooms for the first time, and I talked in detail about my trip. This site isn't "shady", it's a forum. I'm smoking a bowl, literally, as I type this too. Just woke up.