A car wash cleans the surface; detailing restores and protects it. They are different jobs with very different prices, and knowing which one your car needs stops you paying for more than you use.
If you park outdoors or near the coast, salt and grime build up fast, so a regular wash protects the paint. Detailing pays off before you sell — a properly detailed car photographs better and fetches more. Ceramic coating only makes sense on a car you'll keep for years, not one you're about to trade in.