Being around for 20yrs I have seen there are 2 major groups (and a few sub groups) that tend to lose money or "get ripped off" on real estate deals. 

1. "This deal is amazing!!!"...."okay its not so good, but I can make it work"...."Okay, I do it and cut corners"...."I won't get permits or put on a new roof".....

These are the people who desperately want to make a deal work so they try to get the numbers down by delaying turning on power/water, hiring "handy men" instead of skilled trades (and hiring the cheapest one they can find). 

This typically turns into the "guy" not finishing, doing horrible work, delay's, damage causing additional work. Most of these "guys" just want work. And most believe they can do a good enough job to satisfy (intimidate) you enough to pay them....something. 

This group of "investors" typically spent no time educating themselves on how construction/trades work and how best to manage working with them.

2. Cocky, and think they can "figure it out as they go" or that they can throw money at the problems.

These are the people who are 100% emotion based investors. They LOVE the house, they LOVE the neighborhood, they LOVE the feel...

These people typically get swindled by the flashy contractors with the embroidered polo shirts and f250 trucks. (4x4 lifted). These guys will sell you on extra's that are a good idea at a rate that would make a furniture salesman blush. 

Don't let the fancy company card and full FLASH website fool you into thinking that the quality of workmanship is as well thought out as the sales pitch. An A+ rating w/ the BBB can be purchased and so can a bunch of "reviews".

3. The people who don't even get that far. They spend all their money on seminars, boot camps, bus tours, and the rest of the regurgitated tactics the gurus use to suck them dry.

There is absolutely nothing wrong with hobbies. I know way more about NASA than necessary for a guy who will never go to space. But I also don't lie to myself about that and thus can't get talked into "space camp". Knowing why your doing something is just as important as what your trying to know.

Knowledge saves time, energy, imagination, and information. Get you some.