First Rehab: WHERE TO START???

[Justin Rockitter]

I am in the process of searching for my first brrrr investment. I found a duplex and after analyzing comps and having my realtor estimate rehab costs, it seems to be a good investment. I am using a hard money lender. What are the steps I should take to get a solid estimate for ARV and rehab cost. Do you suggest I bring in a contractor for a bid? Do I even have time to bring in a contractor for a bid? Do I just take my realtors estimate and add 10% for a cushion? I know there is also a time crunch and I am a little overwhelmed with how to analyze this deal and have it approved by my lender in time before someone else snatches it up (if I do end up wanting to buy it of course).