I'm not sure if you're driving down or flying, but lining up your stops on Craigslist seems like it would work a LOT better than buying scuba gear from a pawnshop. I don't normally picture pawnshops as a source of life support equipment. Now this is just my own kinda negative reaction. I'm sure that the OP has all the requisite skills and talent to ferret out the wheat from the chaff in a pawnshop.
I'm not for a moment suggesting that there are no pawnshop employees who are also not avid, knowledgeable divers, but I sure never ran across any.
I used to buy a lot of used gear - nothing for my business - that was all new stuff - but in south Floriduh, I did buy some used stuff. Mainly tanks, but some other stuff like Force Fins on eBay. No regulators though. Those have always been new. All of the tanks that I have now, and I don't have all that many anymore like some people on here have - they were all bought new. It's a long term investment on damn near any dive gear except wetsuits, and if you buy wisely, and buy ONCE, even new isn't so bad.
Even wetsuits last. I have a shorty that I used for Japanese intro dives in Kaneohe Bay and surfing on the North Shore of Oahu that I bought in 1984 and still have. It did shrink a lot in the interim so it's tight like a bastard. Maybe I'll return it to XCel wetsuits and caution them against using that shrinking neoprene.