You will know in 6 mo. how the rest of the homes or jobs will go and how the payments are being made from the builder. Talk to other subs that the builder uses and ask questions. IF everything looks good, get your feet wet and make sure you are making money. Stress to the builder or developer if he picks you apart on prices that you need to make a reasonable profit just like him to stay in business and support your customers. If he does not see it that way- walk and let him learn the hard way.