You may want to request the construction drawings / plans for the utilities that were installed to help better understand their impact to your property. 

I just designed and finished installing a 1314 sq foot home.

@Erwin McClain how will software go beyond enhancing your DIY management skills and actually replace a PMC?

Just from a manual inspection with my agent, I estimate 20k at least in repairs, that in my opinion are not ticky-tacky (gutters/water management is broken, Not enough support poles in the basement holding up the house, poor installation of a front porch that is putting pressure on the internal brick foundation that is starting to bend in).My gut feeling is that the seller will be opposed to reducing the price based on conversations with my agent and the seller's agent.

If you're going the DIY route the course that Trevor/Keith are putting together would be a great start.

But comparing rates on commercial (non standardized mortgages) is like asking what’s the price of carpeting without specifying the quality, type, color, installation, warranty or anything else.  

What is the cost to have them installed?

I’ve installed DIY split systems myself.

Should I replace the cabinets and install slabs?

I have verified with USPS that each triplex address is in their database and that there are no issues with the location and height that I would install it at.