In addition, most inspectors will say "looks like the roof needs to be replaced, but recommend getting a licensed contractor to evaluate". skip the middleman and get the contractor. 

@Chelsea Nichols If the property is one of a kind you would probably want to use a cost based approach of evaluating rather than a sales comparison approach using comps.

I am in the process of evaluating sub dividing a property and building a house.

Wholesaling is hard but you just need to understand your buyers they are far more likely to be flippers so you need to evaluate the deal on that basis more than as a rental, although there are buy and hold investors in SoCal. 

One big upside is that the mortgage will be evaluated based on the performance of the assets and less so your personal financial situation.

Meanwhile the person in charge can also help with me with finding and evaluating new deals.

Since investors evaluate many projects which don’t work out for the contractor, the contractors usually become very reluctant to serve as your budgeting agent.I recommend finding one contractor you trust well and keep working with him/her.  

Macro environmental shifts SHOULD impact micro evaluations.

You can know the formulas on how to evaluate deals perfectly but if you don't know your specific market, you wont know what numbers to plug in the formulas.

However, while I was evaluating to replace or repair the roof ($200 for repair) as I have to pay $3k from my pocket for a replacement.