I was able to earn this on level 01 on Story Mode on Normal Difficulty.
Feel free to do it on Easy.
I first built cannons blocking the top left and bottom right roads, and one in the middle of the rectangle.
After wave 2, I started upgrading them to yellow.
During wave 5, I started upgrading them to red.
During wave 13, I built 2 more cannons near the core housing and upgraded them to red.
During wave 18, I built one more cannon near the core housing and upgraded it to red.
I used the orbital laser during wave 20 to kill aliens from wave 19 and wave 20.
I had 5070 resources by the end. With each red cannon tower being worth 1050 resources, you can just sell these to make it to 10k.
This achievement should unlock at the score screen.