Hints:

Take over enemy structures for money:

First send in one of your Yuri Primes into (an IV tank if you can find one) the enemy base and push the expand button or click twice on him. Then you sell it and get a lot of money for it

Two Yuri Primes:

To get two Yuri primes, you must build a barracks, war factory, battle lab and a cloning vacts. Then you buy a Yuri prime and a second will come out of the cloning vact