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.
Dander is an informal term for a material shed from the body of various animals, similar to dandruff. It is composed of skin cells, and can be a cause of allergies in humans.lder etymology has it that dander is a dialect synonym of dandruff, possibly from Yorkshire in England. Dander is microscopic, and can be transported through the air. Through the air, dander can enter the mucous membranes in the lungs, causing allergies to some individuals.