Mobile detail

A friend of mines nephew started a mobile detail business and I've seen some of his work that looks pretty darn good. I talked to him today and he said he can come do my truck Friday. I'm just looking to get the exterior done before winter, I usually do it myself but I am limited due to some back problems right now.
For $85 he will wash, clay, wash, wax / buff, minor scratch correction, do wheels, tires, window, etc... seems reasonable to me. He charges $185 normally for a full mobile detail inside and out, again that seems cheap. One other thing I was a little taken back by, was him saying he could do the whole exterior in about 3 hours. Does this sound right? All i provide is a hose and extension cord.
If it goes well I plan on having him to a full detail every spring, then exterior wash, clay, wax every fall.
We did not discuss what products he uses but I'll check it out when he gets here. For me, right now with my health, the clay and wax is worth it to prep for a snowy / salty winter.
Anything I should check on or ask when he gets here? Such as using a sealant rather than or in addition to wax.
I'll post pics and I'm sure he will too on his Facebook site.
Thanks everyone

 

I just did @Sean266's truck in about 2.5. Just exterior. Wash, clay, polish, glaze, winter wax.

 

Should I ask about a glaze or sealant? I'll gladly pay extra.
All I really think that I need is (and all I'd do myself) would be clay bar and wax.

 

@WarEagleSteve @1BadTundra @smslavin @Sean266

 

I like the glaze as it adds a bit of depth to the color. You could get by without it.