Ron, people are selling off pullets due to feed prices going up. You may get lucky enough to find 6 birds at POL. Yes, you are going to pay more, but you are also missing the expense of chick feed, electricity for constant heat for 6 weeks. You will also miss the absolute cuteness of chicks. Watching them suddenly drop where they stand, which will freak you out if you aren't forwarned, which now you are, and sleep. Then jump up after a short time and take off again. The chicks chest bumping each other, running over top of each other, zipping across the brooder like theres a bug up the keisters.. Teaching them that you are friend, food man... BUT If you get chicks, which I personally see no reason not to, since I have chicks right now, but you will be raising them in your basement for 2 months... If you plan to start taking them out of doors before the move to the coop, for play time in the yard, you will need to bring a heat lamp out with you, so they have a place to run to warm up then go again. This wouldn't be a hassle if you had a mama raising them, but since you'd be raising them, wow... what a pain in the butt. You could do it, but you'd also have to take into consideration, that in December, they will not have the nice temps of your basement, even if you have a typical MI basement that is cold as heck. Actually, if you have a basement that does get cold as heck, then that would make the transfer easier. My old house would get so cold in the basement... OK... in the 50s... Well anyway, it'll be more work for you. Less work for a hen to do. You could always put a heat lamp in the coop in December when you move them to it, but be prepared for power outages and have a back up power source on the ready. A sudden drop in temps when the birds are not feathered for 15 degree weather... well you get the picture. So, all in all, it really depends on how much work you want to start out with.
Personally though, since your coop is planned to be complete in December, then that is when I'd get chicks. If there is a hatchery near you that you could drive and pick them up from, which would be better for the chicks, that'd be the best option, or even from a private party who is hatching what you want. You'll have 6-8 weeks of raising them in your basement. By the end of January/February (I'd shoot for getting them at the beginning of the new year so they'd go out in February) you can move them to the coop, minimal heat lamp will be needed, and by May you should have eggs.
Sorry if this post seemed to be rambling. Some days its hard to be coherent when my brain goes faster than my fingers... and my fingers try to keep up... LOL