Then, you can include a portion of the REAL shipping cost in the pledge if you want (which is recommended) because people have zero clue what shipping really costs and will balk at anything over a certain amount that their used to.
In my personal opinion shipping cost should never exceed the cost of the pledge level someone backed for. Even though I see why a pledge manager can be useful, I don't recommend charging shipping in a pledge manager after collecting the funds. The only time I agreed to do that, the shipping turned out more expensive than anticipated. As a backer, I want to know what I need to pay immediately in one go. No late charges. No surprises. I know I am not the only one.
Besides, using anything other than the Kickstarter system increases the chance of people missing the email telling them about the pledge manager in their daily pile of junk mail. As a project creator I wouldn't want to responsible for taking someone's money and then not delivering because they forgot to add shipping later.
I've never suggested (nor would I ever suggest or recommend) that shipping costs should exceed the pledge level. That would be a sure fire way to lose backers or get an earful from those who were not aware that would be the case.
The only time I would personally consider collecting shipping via pledge manager would be in the case where there could be a huge increase in the weight and/or size of the game through stretch goals.
That said, I would rather manage my stretch goals so that they are already accounted for if reached and so that they don't add a significant amount of weight (I'm not particularly interested in adding a zillion miniatures to any of my games, for example).
It's almost $30 x 500 = $15,000 manufacturing, freight and expenses.
500 backers @ $35 = $17,500 (My Funding Goal)
500 x $13 shipping = $6,500
$17,500 + $6,500 = $24,000
My Profit = $2,500
Those are the "correct" figures... I'm not going to go thru all the trouble of a KS and not make a little profit. What's the point otherwise?!
I'm trying to get the Reward level as LOW as possible and my profitability a bit... Which can scale with more backers.
Note: This is NOT a 5x multiplier between COST and REWARD... It's like $20 to MAKE and $10 for expenses (Art, Writing, Graphic Design, Ads, Prototypes, Review fees, KS Fee). That's why the margins are so *tight*. I'm only making about $5 per game sold.