is it CHEAPER to buy a SHED or to take the DIY route?

I’m about to build 5 sheds in my home backyard and compare the price of DIYing it, or buying a prefabricated shed, or to hire a professional contractor to build them for me. I got quotes from contractors, and did comparative pricing on prefab sheds. In the end, I decided to build them myself and I’m going to break down for you the cost and timeframe. Templates ⬇️ Concrete mixer: