I won't speculate on the nature of the 'sniping' or the communications between the sniper/s and those offering said items, but I will make one observation. It looks like you took 21 hours to respond to either offer. I have to confess that my sense of reality has been so influenced by instantaneous internet communications that when someone doesn't respond to me within a certain time frame, especially in regard to exchanges of goods or other offers, I assume my correspondent is not interested.

Again, I'm not suggesting that is what happened in this case, only offering insight into my own psychology under similar circumstances. In fact, as to my own sense of etiquette, I would have tried contacting you first and then only proceeded with other interested parties if you declined or didn't respond in perhaps another 24 hours (but this may be the real question - how long to wait?).