As much as I like S&P feeds I don't really care for their chick feed. The grind can be chunky and I had a harder time convincing the chicks to eat fermented feed (they liked it dry but I don't want to feed it dry). I ended up feeding my fermented S&P starter to the hens (who were VERY happy to...
Yeah that little container of chick grit I posted above will last me several more generations of chicks... it's really hard to use it up. My feed store has a bulk section so I only bought a scoop of it.
The large grit I buy in 7 lb bags. I only recently bought my second bag with my hens going on 3 years old, so 1 bag every 3 years?
The oyster shell I buy in 4 lb bags and I do go through faster, maybe 2-3 bags a year? During winter I don't put out any since no one's laying.
1. You can feed all flock for life if you want to simplify, or if you prefer to go chick > grower > layer, then start layer once they're all laying or close to it. I've never had a chicken lay at 18 weeks as I don't have production birds.
2 & 3. If you don't buy into organic, save money and...