Contrary to a common assumption, the price of a fiberglass shell doesn't really depend on the city: our price range, delivery and installation included, is the same everywhere in Morocco. The only cost item that can genuinely vary from one city to another, because it depends on ground conditions, not location itself, is earthworks.
Casablanca
The densest market, with a large share of rooftop terrace projects in apartment buildings (no earthworks in that case) or on plots with sandy-clay soil that's generally simple to excavate, unless rock or a high water table is present on the plot.
Marrakech
A market driven by short-term rentals and riads, where site access (narrow medina alleys, interior courtyards) can specifically complicate and raise the cost of earthworks, particularly when machinery can't enter the plot directly.
Rabat
Garden plots that are on average more generous than in Casablanca, with direct access for earthmoving equipment, generally the simplest case, and so the least costly on this item.
Agadir
A market driven by tourism and golf resort residences, on ground that's often sandy near the coast, generally favorable for earthworks, though every plot remains a specific case to check on site.
What really makes a quote vary from one city to another
Soil type (sandy, clay, rocky), the presence of a high water table, and site access for earthmoving equipment: these factors, not the city itself, explain the final quote differences on this item. The base range (shell, steps, equipment, delivery, installation) stays the same everywhere, see the full price grid.