$10 / 100 for annealing is expensive - especially as an add-on for otherwise fully prepped brass.
3-4 cents per case is more on the mark based on what i've paid from several vendors in the past.
thats also the price i've used to calculate my "paid for" price on my annealeeze annealer - still got a couple thousand more cases to go though
just thinking out loud - buy some milsurp brass cheap (raw range brass) and send it to someone who does just processing. you can buy all LC cheap from someplace like
valhalla distributing . $125 gets ya 2400 cases and ship them direct to your processor.
there's a guy over on the
300 blk forums that will process for the cost of brass - including annealing. he seems to be very well regarded by those who have used his service. he does this at a rate of 5:3 (you get 60% of your brass back).
ship him the 2400 from valhalla - and for $125 you end up with 1440 pcs of full prepped 223 ready to roll. even adding on shipping back to you you're gonna be at around $0.10 per for ready to load, annealed lake city.
or you can just pay the $5/100 rate he's charging and have the whole lot fully processed.
since you're looking to stockpile for a couple calibers - this might be a real valid option. $250 or so would get you 2400 pcs to work with. enough to year sort the LC brass and have several good sized batches of brass to convert.
food for thought!
again - just thinking out loud