Most companies make "police grade/for LEO only" models just so distros and retailers can order them at lower prices, and then pass on the savings to the officers. If thats what you are referring to.
Rockj river makes "Leo only" rifles that we sell, they are the same as the operators, just with a different roll print on the mag well that says "LEO Only." These are Semi Auto rifles as we are not a class III dealer, but still LEO only sales. Same with the Glock LEO packages, they come with one extra magazine and with factory Tritiums, which Glock doesn't offer on civilian models any more.
Also during the AWB (assault weapons ban) they had LEO only marked magazines, these had more than 10 rounds. If a mag was made before 1994 when the ban was instated, it was grandfathered in and called "pre-ban" normally stamped on the mag or receiver. THose were worth a premium because they were grandfathered in and legal in most* places. Now pre ban mags and firearms don't command any premium other than Pre ban Colt AR15s as collectors.