Get mulitple proposals, not quotes. Understand what you get for your 10%. Does he have his own crew? What does he self perform? What are the hourly rates? Who will be responsible for the day to day supervision? Is that billable time? What's THAT person's experience building new homes? How many projects does he take on at once? What are the lot/design specific issues? Has he dealt with those issues in the past? Is he currently licensed as a new home builder? If not, who is taking on that role? Does he have a relationship with the architect you've hired? 10% is not a "deal" if the guy has no experience. Some companies charge upwards of 20% (I think that's crazy) but usually those companies will have a huge team working on your project. Multiple quotes with thorough comparisons and vetting presented to you. That's not always a better way, but maybe you like that sort of thing. I charge 10%, have 24 years experience as a ticketed carpenter, I do two projects at a time and supervise them with my partner who has the same level of experience as I do. When I can't be there, he is. There are guys that will build your home for way less than 10%. They will rarley show up on site. How much they're charging shouldn't matter as much as what value you're getting for that money. Good luck