Well, there's always crowdfunding... I actually think it wouldn't be such a bad idea. Just show that the company has a good history and is able to produce those devices with or without the crowdfunders' money. Explain that the reason for the upfront crowdfunding payment is that it only makes sense to produce from 5k devices onwards, otherwise you would run at a loss. No endless options, just 'this is what you get, if you don't want it, don't fund it'. No 'if we reach this goal, you get this extra'. Of course, if certain options like device colour wouldn't affect the production costs, they can be included. And naturally, an 'unsuccessful crowdfunding = money back' guarantee, but I think with the necessary publicity this could attract the critical mass required for success.