The NTAG212 chip was launched in 2013 alongside the NTAG210, NTAG213, NTAG215 and NTAG216. The NTAG212 holds a similar amount of memory to the NTAG213 at 128 user bytes and while it has some more features than the original NTAG203 chip, it's not as full featured as the NTAG213, NTAG215 or NTAG216.
The NTAG212 is very difficult to find and in reality doesn't have a particularly defined place in the market. Unless you are in the market for a very large quantity of tags, the price difference between the 213 and 212 will be nothing. In fact, because supply of the 212 is so rare, you might end up paying more for a chip that has less memory and less features.