You didn't write how much 'sweat equity' you put into this place, but it was likely well worth it given the $400K cash out.  

Just wondering can you ever catch a great deal on the market  and if so what’s stopping you from taking advantage?

I can easily drive by to see if the grass is cut or the blinds and screens are all torn up. 

I use excel , but many times I forget to add any expenses and then it messes up the calculations.How do experienced people do it ? 

We ended up going back to the tried and true Excel Spreadsheet.

Of course your other debts including student loans go into the mix to come up with your total debt to income but the income needed  is a lot smaller then a lot of borrowers in your situation tend to  think.  

A few friends of mine were just straight up taken advantage of and ripped off and lost a lot of money even despite the market moving in their favor. 

The reality is you have to pay for services like this and be prepared to eat the cost if the deal doesn't pan out.

Lived in dumps that I fixed up and sold or rented while working 50+ hours a week at my day job. 

The “hot tub show” models will work, but you will do more work on them in the end.