theemerichfam
In the Brooder
You want young pullets, near point-of-lay, if you ask for "adult hens" you might get some that are 2 or 3 years old and not laying well any more. There are a lot of deals out there that really are "too good to be true", including chickens. Just be aware that not every seller is trustworthy. That said, older chickens for sale are pretty scarce, especially this time of year. Sometimes you can find some if you lurk in the BST (buy-sell-trade) forums here, or on Craigslist. Personally, I won't allow birds older than a few days into our flock. Too much risk of bringing in a disease.
IMO, this is a perfect time to get chicks and raise them to lay next spring. They feather quickly and can be moved outside in a few weeks, where they adjust to the cooler weather gradually as the seasons change. With no need for supplemental light, they should start laying around March.
Of course, I might be making that case because I'm overrun with surplus chicks right now . . .
we have 9 Rhode Island Red hens that are about 6 weeks right now. we just incorporated them in with our 5 month old silkie roosters.
I also heard from my dad that you need to rotate your flock every 6 months, now he has never had chickens so I don't know about that, lol.