Unless your company is paying to transport the bike, you might be better off to wait until you get there to buy. Shipping a bike can cost about $100 or so, and that would easily offset whatever you think you are saving now.
While some are happy with Kmart bikes, you need to understand that the assumption is it will not be assembled properly, so you will need to adjust it (or have it adjusted). Also, as in many other parts of life, with bicycles, you get what you pay for.
In my mind, used bikes are a good deal, but they come cheaper in part because you have no warranty, and there is at least some minor wear.
Test ride a few bikes and figure out what you like.
If drop bar bikes are tempting, you should realize that you don't have to ride on the lower portion of the bar, and in fact, many of us spend most of our time riding on the brake hoods or bar tops. I only say this because you don't have to feel like you can spend all day in the drops to be able to ride a road bike... do whatever works for you.
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Slow Ride Cyclists of NEPA
People do not seem to realize that their opinion of the world is also a confession of character.
- Ralph Waldo Emerson