final-fantasy-15
In the Galdin Quay restaurant, there is a spa in the back right that allows you to get a massage. Ignis pointed it out and hinted towards getting one, so I tried it out to see what happened. Noctis however did not appear to like it and bolted from the bed.
Why should I get a massage? What purpose does it serve?
I have not found any means to obtain bulk lots of ore, so far in my gameplay (Chapter 6 30h+).
The best way to gather ores is to speak to a local restaurant proprietor, who will mark the local procurement points on your map. The pickaxe icons are the ones to keep an eye out for.
Then you'll need to visit these spots and collect the ore. The procurement spots do seem to regenerate after a time. So you can 'farm' these ore nodes by revisiting them once they've regenerated. The icon will change from grey back to yellow.
Unfortunately I haven't been paying enough attention to notice if certain ores spawn in the same spot each time, so that you can gather multiples of the same. I know the treasure spots do contain the same items every time though, so the ores may well do as well.
Receiving high grades, you are getting some bonus experience, up to 40% (getting all grades A+).
Full breakdown of Finesse and Offense can be found here.
Since the Dec 22 2016 update, there are 3 new accessory items which reward additional AP for getting A+ grades in each category.
Best Answer
There really is no purpose to getting a massage in Galdin Quay. In fact, the fact that you can even get a massage is listed as trivia in some places. From the Galdin Quay wikia page:
And from the IGN walkthrough for The Errand Prince:
It seems that this scene is merely added for humor, however, it's noted in this thread that Prompto will take a picture of the occasion, so that seems to be the one thing that will come from it.