Steve - Do you have previous airbrush experience? Is the H&S new or used?
The other responders offered great input, likely best to buy the simplest and easiest to use airbrush for a starter. Buying used can be a real gamble, maybe OK, maybe not. The major authorized dealers like Chicago Airbrush and TCP offer good sale prices, I have bought major brands like Badger and Iwata at very steeply discounted prices.
Do you want double or single action? Many of the FSM highly skilled modelers stay with single action and produce spectacular results. I really recommend, if you haven't already, that you take a good look at Don's Airbrush website. It's really loaded with information to help you gain general airbrush knowledge, and even to help with an airbrush type, or brand selection for purchase.
Good luck with the hunt.
Patrick