For those that don't know, the suicide trick is where you kill your man at the very end of the gray board in order to get the gray board bonus, and also get the super spray on the gold board. I decided to count on how many points can be had this way if EVERYTHING GOES RIGHT. So that means no early deaths on the gray board, and getting the super spray in a timely manner on the gold board.
OK, time to do the math.
Gray board bonus 7500+the 5 potted plants(500) + 5000 perfect bonus= 7500+2500+5000=15,000
Gold board bonus 5000+the 5 potted plants(500)s+ 6 blue moths(300) + 2 worms(300)+5000 perfect bonus=5000+2500+1800+600+5000=14,900
Blue board bonus 7500+the 5 potted plants(500) + 5000 perfect bonus=7500+2500+5000=15,000
Gray board bugs 4 queen bees(400)+8 blue moths(300)+8 yellow moths(700)+12 beetles(700)=1600+2400+5600+8400=18,000
Grand total=15,000+14,900+15,000+18,000=62,900
So optimally you can get 62,900 per sacrifice of men.
Of course things get screwed up along the way. flowers get stolen, and you don't get the full bonus because you die early. So a more reasonable average is going to be around 55,000.
So let's say you have a 5 man 400,000 point start. That means you have 32 men left. If you can average 55,000 a man through sacrifice you can get 400,000 + 32 times 55,000= 400,000 +1,760,000 = 2,160,000
So basically the most you really should expect from the sacrifice technique is about 2,160,000. Though you lose an extra 55,000 points every time you die twice on the gray board. So 2 million is possible if you die twice on the gray board 3 or less times.