By the way, correction: When I said 20,000 in kills, I meant 20,000 money, not number of kills. Thats probly why people rated my comment badly, sry for the misunderstanding.
I find I can rack up about 20,000 in kills without leaving the sector. How? Wait for friendlies to damage enemies, then shoot the enemy with space bar laser cannon. Lol. Needs no ammo, just energy.