ill be able to do most of the work myself only paying for the electric and final pressure test.   

From experience if a building has been vacant for some time the gas lines need to be pressure tested, if the electrical meters are locked out or removed they need to have an ESOP once inspected & the required permit(s) signed off. 

HGTV shows overblow the mold issue - most of the time you're talking about solving the water issue, then cutting out some drywall and washing things down with a bleach solution.

Even if plumbing is all new in the building if main is bad from the street to the building you can have water pressure, leaks in ground, and back up issues.That doesn't even get into knob and tube wiring, lead based paint, asbestos, old heating and cooling systems that are now outdated and must be replaced, ancient water heater systems, unpermitted or grandfathered additions over the years, etc.Ask the owner if they have a recent engineers inspection report of the property they can share with you.

@Blake Wash it really depends on how the real estate market is in your area.

However, I'll admit I'm avoiding reading up on the topic in order to keep my blood pressure somewhat near the levels of the living

With prices already at max and buyer fatigue inventory should increase slightly but pressures from the low cost of money will not significantly alter pricing.

Do not fall to the pressure of buying at the risk of doing financial harm. 

Should be enough pressure to make them back off. 

But they also requested new flooring, new mini-blinds, new washing machine (it wasn’t broken…just a little noisy).