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.
gander - 1. In Britain, a married man . 2. Or: take a gander , a look or glance; take a look. 3. A stupid or silly person; a ninny. 4. In gay terminology: a) The man who assumes the active role in anal intercourse, a variation on gooser. See sodomite for synonyms. b) An active male homosexual.