If were gunna talk the whole flock, coop included...
I breed showbirds, so they're a little more expensive than layers, but here goes (I'm going to try and average it out)
My coop cost around $700 to build, then I built a few small coops on the side, there's another $200.
My original birds all cost me $100+ each x 13 = $1300
Feed costs about $80 a month x 12 months x 7 years = $6720
Shavings are $20 per month x 12 months x 7 years = $1680
Replacement of cracked waterers, etc around $30 per year x 7 years = $210
Show entries, which are around $40 each x about 9 shows a year x 6 years = $2160
Supplies for each show $10 x 9 shows a year x 6 years = $540
Misc supplies (meds, bands, etc) about $75 a year x 7 years = $525
Total of about $14,035 and I'm sure I'm forgetting stuff...not even going to try and calculate all the gas I've gone through for these birds
The most I've spent on purchasing a single bird was $250 + $50 in shipping.
Here's a pic of her, she filled out much more than in this pic and became a stunning bird that produced excellent babies.
They're not cheap!