When I left Germany, I arranged for a local tax agency to help prepare my taxes each year, since that is a necessity. 

A strong valuation and even pre listing appraisal and/or inspection can sometimes be a worthwhile investment but not a necessity. 3-5% commission for what is effectively commercial property is common. 

@Emelie Deans Finding a CPA that specializes in real estate taxation is definitely a necessity to be able to take advantage of all the tax strategies. 

I'm a fan of running lean, but you're one bad month away from borrowing for necessities.

The pickleball courts we have added to our clients homes have done really, really well - but I assume in this market a pool is almost a necessity.

They are dense reading by necessity. 

When you reach your goals wouldn't it be a necessity to have your health so you can enjoy your achievements for a long time with your loved ones?

Two years ago I decided (out of client necessity) to reapply for my NMLS mortgage broker license to provide more robust mortgage options and services to my clientele.

So back to a NECESSITY for ANY buyer having documented evidence of the terms surrounding there actions in showing to definitively make clear agency status. 

For example declaring a monetary war thus necessity, or a cyber war etc etc..