The second one is charging hourly. We tend to prefer hourly fees on projects that are particularly open ended or very small scope. Our hourly rates are currently between $60 and $120 per hour depending on who is doing the work.
The word sonder exists, though. It means to probe, and in a more specific use, to test the depth of something. The word sound (as in the water feature) is a cognate, both related to the Old English sund meaning to swim, or the sea. I can't really think of an English equivalent that's specific beyond mere awareness.
The definition of a gander is a male goose, a look at something, or someone who is silly or foolish. 1  An example of a gander is the male or males in a flock of geese. 2  An example of a gander is a look at a new community park. 3  An example of a gander is someone who constantly plays pranks.