I'd find another dealer. Siemans makes good aids, but there really
isn't one brand name that is head and shoulders above the others.
Your dad needs to call around and check price. The going rate for a
completely-in-the-canal aid in this area (Salt Lake City) is from
$1200-1600. I realize that there is a huge regional variation, much of
it dependent on competition, but $4000+ for an aid is simply too much.