1. Make sure you dont have rapido cheat enacted.
2. Build a diplmoatic minestry.
3. Issue the blueprint edict for us or russia (russia is best if you have a choice.)
4. Build as many of the buildings you get half off (DO NOT LET THEM GET CONSTRUCTED ANY.)
5. Cancel the edict.
6. Stop the construction of the buildings for a refund.
7. Since you get double the refund you get double the money back.