These are professionals with additional training and a stricter code of ethics.

I will bring this up to my PM as a ticket item nonetheless.

I am training our son to basically do the rehabs but there is a learning curve.  

You could go to work for a remodeler too perhaps giving bids, selling service or see if they will train you to be on a crew.You could also go to work as an ISA for one of the big wholesalers. 

If you have no facts, then yes an appraisal can be your ticket, but also keep in mind how your state manages assessed values.

However, the right Broker is very important when first starting because they can train the agent how to run their business and find success.

Generally larger commercial properties and shopping centers are easier to classify with hard and fast rules, but to the points above the residential areas really move very quickly and have way more nuance than most people care to admit.zip codes are generally way too large for my liking at least in my market to provide any kind of insights other than macro level economics but even then highways or rivers that cut through a zip code can end up with totally different trade areas.we can get pretty granular with cellphone data and with grocery center data to understand the trade areas and their true boundaries, but that kind of data pull is generally only cost effective for investors doing larger scale projects or developments, and honestly we still just end up getting on the ground and feeling it out, so I generally tell people that the money is better spent on a plane ticket and weekend trip in the area you are looking rather than any kind of "trade area" level data studies.and generally B class in 1 area means something different than another. 

Spend your time and money learning how to avoid that kind of situation rather than learning from on the job training.

Here’s my honest advise; consider studying for and obtaining your real estate sales license, and obtain a part time position with a real estate agency that will provide training, guidance, and oversight.  

I actually tried to beg the city to let us sell it to the fire dept to burn it down for "training".