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.
1. often meanders A bend, turn, or winding, as of a stream or path. 2. A portion, side trip, or episode in a longer journey. 3. A passage on a subtopic or digression in a longer piece of discourse. 4. An ornamental pattern of winding or intertwining lines, used in art and architecture.. meander-a bend or curve, as in a stream or river. oxbow-a U-shaped curve in a stream. stream, watercourse-a natural body of running water flowing on or under the earth.