By your reasoning:

$4400 Prize - $220 buy-ins (10 Step 2) = $4180 profit
$4400 Prize - $4300 buy-ins (10 Step 5) = $100 profit

Let's say all I do is finish 5th twice out of my 10 buy-ins and 7 Step 5 tries:

$400 Prize - $220 Buy-ins (10 step 2) = $180 profit
$400 Prize - $4300 Buy-ins (10 step 5) = $3900 loss

Pretty easy to see why I would chose NOT to do that

(Not to mention that I never said I could finish in the money 6 of 7 times on a Step 5, and I only had a couple hundred bucks to start jackhole)