In all honesty i would not buy any VTC5 or VTC4 from anywhere. Sony has released stamens saying they discontinue those and stop production on those in april of 2014. So more than likely any that are out there are not real or extremely old. but thats just my opinion and i don't want to risk it.
Sony NEVER intended for the VTC4 or VTC5 batteries to be sold on the open market. They were/are manufactured to be sold exclusively to OEM in protected battery packs for cordless power tools. I believe Sony made the statements about unavailability because they don't want the liability issues and potential lawsuits of people using them in applications (vaping) that were unintended and the fact that so many fakes are available.
From a historical perspective, since these batteries seemed ideal for many vaping applications, some of these Sony's were obtained by battery vendors on the open market. They became so popular that their availability became inconsistant, so some disreputable folks began making fakes from sub-par battery cells to take advantage of the situation and make a quick buck.
Sony has never stopped making the VTC4 or VTC5. They are still seen in cordless power tools. Their availability to vapers remains inconsistant, in part because the main manufacturing facility in Japan was destroyed in the earthquake. New facilities are now in place in the Philippines and China.
Reputable battery vendors (RTD Vaper, Illumn, Orbtronics) will usually have authentic Sony batteries in stock and can verify their source. Many of the Sony batteries found on Ebay or Amazon will be fakes.
Sony never officially released the specs of the Sony VTC4 or VTC5. The VTC4 was independently bench tested to be 2100 mah 30 amps continuous discharge rate. When the VTC5 became available, advertisers assumed it also was 30 amps. Recent bench testing has revealed it is only 20 amps continuous, although it does have 2600 mah. Therefore, its performance will be comparable to the LGHE2 2500mah 20 amp and Samsung 25R 2500 mah 20 amp, but often at a higher cost to the consumer because of the Sony name.