Readers should seek professional advice.

I don't butt into his business and we keep a professional, yet friendly relationship. 

Readers should seek professional advice.

Apply the 70% rule to determine your maximum allowable offer, then negotiate and get the property under contract, ensuring your agreement includes inspection and financing contingencies.Arrange professional inspections to uncover any unforeseen issues, using these findings to negotiate concessions or confirm your repair budget.

And if they are a hobbyist/part-time builder, then they should engage the proper professionals, i.e. a title officer, civil engineer, architect, contractor et al to assist in reviewing the project's feasibility.

Did you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?

Take this time to make sure you have professional photos of the unit taken.

I understand that means paying the right professional for their services. 

They would be better off paying the professional to do it quickly and correctly the few times they will need a garage door opener installed.Even though i open permits slightly regularly, when i open a permit in a new jurisdiction it typically has some unique quirks that i need to learn.  

Work Quality:I hired professionals to inspect the work, and they found multiple issues and evidence of negligence in the construction.