The eagle eyes over at NeoGAF found the listing, which was quickly removed by Amazon Spain. The console lists for €399.99, and falls in line with PlayStation's Andrew House saying the Neo would be more expensive than the existing PS4. He also said at the time that the unit is designed to "complement" the console, not replace it.
If this is indeed the new PS4, rumors have circulated that the unit will have a faster GPU, more processing power, and support 4K image output. Also, it was mentioned that games will be required to run in base and Neo modes by October, which could also lend credence to an October release.
Of course, all this is speculation, but get your credit cards ready for a big October just in case.