The 15% brings the cost of the step down about $10 less than allmoparparts.com and other online retailers. I notice there is a new p/n 82215842AH now on the mopar's site in addition to the 82215842AF (also mopar site) and the 82215842AG (allmoparparts.com)
The 82215842AF (replaces 82215842AC, 82215842AD, 82215842AE) states 2500 only in the description but shows the 3500 in the fitment list regardless. I know it is one of the new re-engineered steps. Now the 82215842AG on the allmoparparts.com site says it replaces the 82215842AF. Given the factory numbering system, it would appear the 82215842AH would be the latest and greatest. So all are the same price, fit the same models and model years 19, 20, and 21. Glad this isn't confusing.