If you don't reach it in time, collect pre-orders. Seriously. Getting an escrow setup in place that in effect gives you a similar payment mechanism as Kickstarter (money handed over to you once the $750k is met; returned if criteria are not met) does not need to be expensive. Even without Escrow I think that if you get close to the target, a substantial number of those of us who've committed on Kickstarter will be ok with taking the risk. And it'd let you set longer/more flexible terms to make reaching it easier.