I'm semi new to all of this and looking at a property in Oklahoma currently listed @ $41000 (IE)  failed plumbing pressure test. 

Fire Sprinklers are typically just a pressurized pipe full of water.

The unit that has the dirty filter might have a broken supply air joint or broken ductwork causing the inside to go negative pressure. 

I am looking at 3bed 2bath deals for $75k to $150k and trying to gauge a solid ARV using recently sold new construction.

@Alla MinchenkovI just recently was in escrow for a home that was as is and the seller had some pressure to sell their home ASAP.

Due diligence began with a home inspection, walk-through's and quotes from contractors for repairs and meter installation, and gauging the market's interest in renting the commercial units.

Paid training will always have its place.. what the guys that do this need to clean up though and what I never liked was the pressure and getting folks who cant afford it to put it on the CC.. the ones that succeeded no problem the one's that were never ever or will ever be cut out to be home flippers just end up in debt.. but who are we to dictate their dreams.. 

A 12' diameter pressure vessel was delivered 6" too short. 

The added pressure of finding a replacement pushed me to do and try things I had yet to attempt.

Honestly it’s a bit of a screwed up way to do things because you’d be wasting peoples time, but one way you can get a gauge of how much it would take to renovate certain parts of the house would be to call a contractor to your personal house and ask them to give you a bid for a new bathroom, kitchen whatever you need to know prices on.