Every site is different
How can the pricing model hold true for every property? There are just too many variables...
The soil conditions vary from lot to lot in the same neighborhood and the required strength of the concrete shell will vary significantly.
Access to property and the required excavation equipment will differ.
The distance to the dump site for the dirt spoils varies, as do the fuel and trucking costs.
The size of properties and setback limitations are different.
The lines of sites from the owners & neighbors property differ.
Existing utilities and locations vary and may require upgrading or longer installation runs.
The structural engineering used on these projects is a generic, a one size fits all plan. They meet the MINIMAL requirements, but are not guaranteed to meet the conditions for your site.
How can they do this? Because most building departments do not enforce the International Building Code requirement that the structural engineering be designed to overcome the surcharges placed upon the structure. Some cities (Los Angeles for example) require soils reports with swimming pool plans and structural engineering. They require that the soils engineer review the structural plans to ensure that the engineering meets his minimum requirements.
Simply put, the swimming pool must be strong enough to prevent structural failure (cracking) from loads placed upon the shell. These loads come from adjacent structures & buildings, up or down slopes, retaining walls, winds, snow, saturated soils, expansive soils, uplifting soils, seismic events, surf or tides - anything that will place a force on the pool.
Generic structural engineering is totally worthless, if the structural engineer has not reviewed the site and a soils report (geotechnical investigation). The structural engineer simply cannot validate the strength requirements without a soils report that defines the conditions below the surface.
These "package" price pools totally disregard the strength requirement, by placating homeowners with a pool builder's own "structural warranty." This warranty does not warrant the pool against cracking - only that the pool will "hold water." That means when the pool does crack, they will patch only the crack - thereby restoring the watertightness. And, when they patch the crack, they will not repair the plaster surface.
Would you accept cracking of your home's foundation, a dam above you in a canyon or a bridge you drive on? Of course not, but they seem to think that this is acceptable.
You want a site specific structural engineering? That's extra!
You don't want the pool equipment 10 feet from the pool? That's extra!
You want to change the shape of the pool or steps? That's extra.
You want something other than white plaster? That's extra?
Oh, you wanted the spa heated? A heater is extra.
You want a gas line to feed fuel to the heater? That's extra too.
You want a tile other that the 6 blue tiles we offer? That's extra.
Oh, you want remote controls of the pool & spa? That's extra too!
You want drains in the pool deck? Those are extra?
It is the old bait and switch routine to which we all try to avoid.
Remember, YOU GET WHAT YOU PAY FOR!
Aquatic Artist, Watershape Consultant, Expert Witness
"Creating water as art."™
Aquatic Technology Pool and Spa