Rehab costs that are under estimated by very wide margins.  

Mind you, this was all at the end of their 3-year lease term.Long story short, the “tenant” was evicted under nonpayment of rent, and finalized after approximately 60 days.

I got several estimates from roofers and the replacement cost is around 13k (it's a ~1600 sqft house).

What I really look for in a agent is can they confirm or deny my ARV and rent estimate and explain why.

They provide free estimates and work with your accountant.

I had an estimate done ($7k) because at this point the sprinkler piping is exposed and I'm afraid that could lead to an even greater problem.

I am getting 3 estimates on the property in the next week but could also do some of the work between my dad and me.

The BP rental estimator tool is pretty good as well and is usually within about a 5-7% margin of error. 

Specifically in SC, though, I would check two things - 1) see if the ATI exemption applies and actually quote the taxes for that particular property on the county tax estimator tool, and 2) get a ballpark quote from your insurance partner on the particular property.

They provide free estimates and work with your accountant.