black suit; mourning clothes; black-suited staff member (e.g. in restaurant, sex establishment, etc.)
persistent; obstinate; tenacious; relentless; insistent; importunate
to appear; to start to appear; to show signs of appearing
extended leave; long vacation
to grumble; to make difficulties
there's nothing that doesn't exist; there's nothing we (I, he, she, etc.) don't have; nonexistent; not in one's possession
after-sales service; warranty service
to ask elsewhere; to try another (store, service, etc.)
to spring; to bound; to be stimulated; to be encouraged; to pay handsomely; to splurge
advance payment; money paid in advance
fee contingent upon success; contingency fee; completion bonus
too-good-to-be-true offers (e.g. scams and frauds); too-good-to-be-true stories
having said that; on the other hand