Glocks are not sold to Police Agencies "at cost, or below". Glocks sold to LE Agencies are sold at a competitive price, similar to wholesale, just like every other pistol. But Agency guns are not subject to the Federal Excise Tax that commercially sold Glocks are subject to.
When I was young and broke, I reloaded my ammo to save money. I used the cheapest lead bullets I could find, almost exclusively, and lots of them.
ALL barrels lead up. I used to use a lead removal tool in my match 1911's that was brass screen screwed to an arbor. This was years before the Glock 17 hit the market. My Glock 23 had 14,000 rds of my lead reloads through it before it ever had any factory ammo through it other than function testing JHP ammo.
I had a class last year in the heart of the ammo shortage, and the range only had crappy lead reloads. Many students were using my Glocks, with several hundred rounds of crappy lead reloads in high heat. I checked the barrels every couple of hundred rds and none of them needed to be cleaned. In my experience, the lead bullet issue is more hypothetical than practical.
When LAPD approved the Glocks for duty, it became almost impossible to find one for sale in LA. Just about every LAPD Officer ran out to buy them. So much for "no officer buying their own to carry".
My shooting partner's duty weapon is an HK P2000 in .40SW. But what does he carry off duty? Glock. In several years of carrying Glock 17's on duty his Agency never had one break, or KB. In two years of carrying the HK P2000's he has seen 4 KB on the range, and several more rust completely shut. He shoots about 35,000 rds a year through his personal G17. In 15 years he has broken ONE trigger return spring.