If you are new to riding there is no way to know what "$1000 bike" you'd want to keep (and actually use) for 25 years. So yes, I agree with the other posters, just get something inexpensive and start riding. The more you ride, the more you'll discover what works best for you, and THEN you'll know what your next, more fancy pants bike should be.
With CL you need to learn how to properly inspect a bikes condition, and it can take quite a while to find a good deal. (Or three or four good deals if you're outfitting the entire family) In my area, people often ask ridiculous amounts for used bikes on CL, even junky ones. Don't get me wrong, there are good deals, but it may take a lot of time and effort to find 'em.
So, lower end bike store bikes can be a good option in my opinion, especially if you buy last years model on discount. Some shops even sell used bikes, that they have reconditioned and tuned. You start off with a quality product, and have dealer support. The only thing they can't do for you is pedal the bikes!