Every experienced flipper seems to have one category they never underestimate. Which expense has taught you the biggest lesson?
When my brother and I were doing flips before Covid. It was carrying costs every time. We expect challenges with the rehab budget, dealing with fickle contractors, permitting, etc. However projects that take a little bit longer then planned or a market that is slow can eat into your profits quickly. We learned this the hard way when one of our flips that was purchased with hard money couldn't sell after many price drops. We held it over a year and had to eat the cost of interest accruing, utilities, insurance, etc. Those things didn't stop because the contractor made some renovations that had to be modified or done over. After that experience we always pad that line item more than anything else.