Hiring contractors and funding the flip

I live in North Dakota and started buying real estate on my own as my husband was not keen on the idea. I have 2 SF homes and a 4 plex currently. My husband doesn't have much time to help me as he farms and his time is kind of rare. I want to buy and flip however I have never done this before. My question is regarding hiring contractors. How does one make money when the contractors in my area charge the going rate? I know I need to get the best price when I buy but even still I think the end result is going to get eaten up by the contract labor. I do as much as I can regarding demo but limited. I do have a line of credit I can access for expenses and labor. Need tips on flipping and hiring contractor.