Is $475 for a underbody detail with POR 15 good?

[sugjavier]

Motor City Auto Spa - Royal Oak, MI | Yelp

Their website is Motor City Auto Spa : 20 years of expert auto detailing in the metro Detroit area

I got my car completely detailed but now wants the underbody detailed too

 

[Valkyrie]

Do it yourself? It's not hard.