The standard Merzouga camel trek leaves the village edge in the late afternoon, winds into the dunes for an hour or two, and arrives at a desert camp for sunset, dinner, and an overnight stay under an extraordinary quantity of stars. The return is at dawn, timed for sunrise over the dunes. It is a well-oiled operation and the experience is genuinely good, even if you are one of a dozen groups doing the same thing that evening.
Most operators charge around 350–600 MAD per person for a basic overnight, including the camel ride, dinner, and breakfast. The spread between basic and comfortable camps is considerable: budget camps offer Berber tent, shared sleeping, and simple food; mid-range and upmarket camps add proper beds, en-suite bathrooms, and a fire. The quality of the food matters more than most people expect after a long day in the desert.
For something more substantial, multi-day treks of three to five days are available, covering a wider sweep of Erg Chebbi and the surrounding desert, reaching nomadic encampments and the fossil-rich areas east of Rissani. These need advance arrangement through reliable operators in Merzouga or Rissani. The 4WD alternative — same destinations, less romance — is faster and more comfortable, and lets you cover much more ground.