It's a pretty clever kickstarter by Reaper. It's clear the original goal was deliberately very low. The pledge that they want you to take is $100 and for that you get a reasonable little swag of plastics, one collector's piece, and a few little nice benefits, you know, forum badge, hat. They "pay" you out of stock they have, production they have, and it's an OK deal that gets a bit better at the first stretch. People like me buy in. Thereafter the deal keeps getting sweeter as later "stretch" goals are met. This works for word of mouth, builds some buzz, and also works in rational-player market theory: as more models are included, you pull in people to whom models are worth less.
The trick is they get their re-tool money now, and then tool up to give you new minis at-cost (to them), effectively making this a zero interest loan that they repay "in-kind" ie., with product, (that you value it, more-or-less, at retail is another bonus to them). I am pretty confident this is how they did the numbers for this... based only on my own wild guesses. If I were in their business, I would copy the hell out of the basic idea: loan, zero interest, paid in product.
And, every second stretch goal amounts to "Hey, people who lent us $100, lend us another $10 and we'll pay you back in more and very awesome product! C'mon. Ten bucks!"