On the contrary, the economy in the US is horrible at this time. With that said there will be plenty of scammers out to make a buck too. Being that you're overseas, I can't imagine how much that difficulty increases.
I've just went months searching for a vehicle for my sister. The amount of overpriced vehicles in deplorable shape is astonishing. Then the cost to have them road ready in safe condition was usually twice the cost of the vehicle. I'm here, in person, and yet I struggled. Blatantly lied to about said vehicles, unbeknownst to most of the sellers that I turn wrenches for a living. Of course once I start pointing out their lies.... their tunes changed & wanted nothing more with me. No bartering, no haggling... I guess they figure they'll sell it eventually to an unsuspecting smuck, at the price they're asking.
So advice... haha, I can't give you any on how to get them to respond to you. But I surely do advise, please be careful when you do handle the transaction & with whom you do business with. Watch out for flood damaged vehicles in the St. Louis area. They are being shipped in from all over flood ravaged areas in an attempt to get rid of them. God bless & good luck!