For my good pard Rooster and Yeti:
You pards are REAL lucky if you get as much loading out of your nickle cases as you do plain brass. I do have some 45ACP and 38Spl nickle plated cases that have been reloaded so many times that around HALF the nickle has been worn off by the carbide sizer, but typically, I get 3 or 4 times the life from plain brass than i do from plated cases. Nowadays I load more 45 Colt than all the others put together. My loads are 99.9% BP, but every once in a while (when I want to shoot my Remington 1875 that doesn't seem to like BP, even with BigLube boolits) I'll load some smokeyless rounds.
I don't have any Starline Nickle cases, however. If their N plated cases are of the same quality as their non plated cases - and I have no doubt that they ARE - they might be better plating and wear better. Most of my experience has been with once-fired Remington 45 Colt cases and factory new Rem. Nickle 45-70 (NOT fired previously) cases. Several of the 45-70 cases that I loaded with Cartridge BP by Goex, split the first time I sized them. At THAT time, I was still full-length resizing, which I quit doing after I heard about "neck-sizing" 45-70 fired cases using a standard sizing die. I have been neck-sizing bottle-necked cases used in my bolt rifles for decades with specific N/S dies, but when I started loading 45-70 - which is almost/somewhat a straight-wall case, I hadn't grokked how to neck size using a F/L die as most of them are for 45-70. (I believe that N/S dies for BP 45-70 do exist, I just hadn't seen them, so when I bought my dies they included a F/L sizing die.)
Like Shotgun Franklin mentioned, plated cases can be left in belt loops, while brass cases can't be left for long. I did have a leather expert tell me that ONE of the tanning processes doesn't react with the brass, which produces the verdigris. (Green crap) He also said that that type of tanning isn't done as much. (Vegetable tanning vs. chrome tanning? Or vice-versa? Or another type altogether, like brain tanning? I don't remember WHICH type he mentioned - sorry!)
Most "Combat Ready" ammo comes with nickle cases, as I'm sure most of you know. Less chance of verdigris, feeding issues, etc. make it "carry ready" preferred.
As suggested, Luke, try Midway.