The $ or price of a after market treatment or coating is NOT the issue. Having a reliable, well made firearm that can protect you in a critical incident is.
Many sworn LE agencies & military units get weapons/equipment treated with aftermarket products(NP3+, Black-T, Bearcoat, etc). They spend $ to PROTECT their officers & increase the service weapon's length of use.
You can buy a firearm & keep it factory stock. You can also get a after market or custom coating to help speed cleaning, prevent wear, rust, nicks, etc.
I've owned LE surplus pistols with Robar NP3 treatments in the past(for sworn fish & game officers). It made sense to me.
Walter Birdsong; Black-T once told me about training LE classes & discussing carry/wear/service of issued weapons.