We're continually surprised by customers who, when comparing two or more quotes for the same specified products, believe they are exactly the same and purchase based on the lower price. The vague verbiage in these quotes does not reveal "the true picture" and the customer often finds out when it is too late that what he thought he was buying and what he actually received are quite different. When it comes to steels common in truck body building there are three distinct issues that should be considered: steel grade, finish and gauge tolerance.
Grade describes the basic properties such as strength, corrosion resistance, formability and weldability. Commercial Quality "CQ" is at the low cost end from which prices increse through higher strength grades (50K psi, 80K psi, 100K psi), corrosion resistance versions ("Corten"), abrasion resistant versions ("AR") and specialty steels with high strength, wear resistance and toughness ("Hardox"). Saying a particular steel is HSLA (High Strength Low Alloy) doesn't fully define the material and is like saying "hardwood" without specifying whether it is oak, maple or cherry. Steel pricing varies significantly due to its attributes as well as market demand/supply volatility. For some perspective CQ recently sold for $0.33/lb, 50K psi for $0.37, Corten for $0.44/lb, AR for $0.73/lb and Hardox for $1.00/lb.
Finish refers to the surface properties which impact the painted surface aesthetic and strength of the primer/steel bond. Hot Rolled is relatively inexpensive but results in a poor looking and performing paint finish unless it treated prior to priming. Hot rolled pickle & oiled (HRPO) is more expensive but results in a much smoother painted surface and good primer bond which better resists corrosion creep. Cold rolled steel, the most expensive, is really only used in critical surfaces such as automobile hoods & fenders.
Gauge tolerance refers to thickness variance. ¼" steel could be anywhere from 0.240" up to 0.265" and still be called ¼". Two bodies made of ¼" steel could vary by 10% if one manufacturer uses low end thickness steel while the other uses material at the high end of the thickness range. Both are ¼" yet one will result in a significantly stronger body than the other.
What all of this means is that two steel bodies with supposedly the same specifications could actually cost quite a bit different to manufacture and perform very differently for the actual customers that purchase them. When it comes to steel truck bodies the old saying "you get what you pay for" generally applies!