Just make it clear that you only get the product if things pan out. The tricky bit is if the money is only there to deliver some of the products. Needs to be so

Just make it clear that you only get the product if things pan out. The tricky bit is if the money is only there to deliver some of the products. Needs to be some protection as well on people taking the money and running, but apart from that users shouldn't feel like they didn't get what they paid for if it doesn't pan out.