It's 'easy' if you have inside connections with the planning and zoning committees and utility companies. I recently developed a property worth about $250k for about $100k. The building process itself is relatively cheap (land + cost construction way cheaper than value of a finished property) and straightforward, everything else is not.

The only reason why I was able to get it done as a random person was because I used a non-commercial loophole to not have to get the inspections that are used as hostile clamp on disfavored competition, and the utility companies that could have charged me a gazillion dollars saw that I was just a guy with a family and took pity on my situation (they are used to dealing with large commercial developers) and gave me the easiest out at every opportunity.

If you are a favored developer you can get things done as easily and almost as cheaply as I did and make vast profits. If not you are fucked and you barely break even because either government workers, or government franchised utility monopolies fuck you at every turn. I lost count of how many times I basically saved $20k-$30k because someone decided not to fuck me that day over some inane detail that in the end doesn't actually make any meaningful difference (the only time I got unlucky -- a utility worker made me redo a survey which cost thousands and then LOLed later that I never needed it, eventually it turned out this person was literally just making shit up which is an astonishingly common tactic when some asshole just wants to delay dealing with you. I was only able to fire this utility company because I was on the border between two monopoly lines which created an unusual point of actual competition, and the next one used a ton of creativity to get the same thing done for relatively next to nothing).