The phone is available in the rest of the world as the alcatel prime 6. Vodafone just rebadge alcatel phones in the UK to Vodafones own brand. The phones are made by acetels owners TCL in China.
From what I read, a lot of budget phones have the nfc capabilities within the removable battery. I just ordered one used online for $25 and had the seller expressly check the battery for me. I agree with you though, it's confusing and rather annoying to have to filter through this way. I wouldn';t blame an employee though, who is likely making $10 an hour and has no way of really knowing everything about every model they sell. They likely looked it up with the same information you have online.
Also the same phone can have different specs and features around the world take for instance the Samsung galaxy note 4 in different parts of the world it has a totally different processor in some countries it is powered by a 2.7 GHz quad-core Snapdragon 805 chipset with Adreno 420 GPS and in others it is powered by Samsung’s ARMv8-A Exynos 7 Octa SoC with two clusters of four cores; four Cortex-A57 cores at 1.9 GHz, and four Cortex-A53 cores at 1.3 GHz. So shop workers may simply Google the phone and be looking at the specs for the same phone but not the one sold in the country they are in ect.
yep, it's a bit annoying trying to make sense of it all. I actually did a couple hours of searching and honesty conclusion was I couldn't buy anything NEW for under $70. That's not a bad price for a phone, mind you, but when all I need/want is an nfc reader, well...
perhaps you checked wrong country, US samsung site says J3 has no NFC :
