Starting resources: 1000M/1000E, max units 500.
You can build 7 metal extractors as how they are exactly in my replay. (you can also replace them with moho mexes if you want). You cant use thermal vents.
You need to start from the same position as in my replay. No cheats and single player game, as in my replay...
My replay (new, because of version 3b):
http://www.savefile.com/files.php?fid=1216167
Final result, about +140M in 20mins. I think its possible to get max +200M in that time.
Lets see what you guys can do :)
Here is the screenshot from my (new) replay:

Use the savefile.com for uploading replays:
http://www.savefile.com/index.php?id=upload
And imageshack.us to upload screenshots:
http://www.imageshack.us