Cost Plus Pricing by GC? Anyone hear of this?

[Bill Dengler]

Im looking into working out of state renovation with a GC. I really like his work, ethics and how fast he gets back to me. I am looking into a foreclosure that needs alot of work and he said that he can do Cost Plus with me. Meaning, I pay actual cost for material that he gets, including his discounts (he gives me actual invoices to pay) and he just puts a percentage on per job. He said he like this because it guarantees him a profit. I thought if he gave an estimate and I paid him that would guarantee a profit, but Im not a GC. I never heard of cost plus. It sounds good but I figured I would check in with the BP community to weigh in on this.