MicroSD card 512 GB while are very rare. Offhand I can only remember a few presents this year models.
Today one Samsung added. The company announced microSD card EVO Plus with up to 512 GB for the price of 290 euros. By the way, it’s even a little cheaper than the cost of a similar card from PNY. In addition, there speed of reading and writing are 100 and 90 MB/s, respectively.
However, if you need a card for a large amount, and to pay for a good smartphone there is no desire, look at the volume of 400 GB. They are on the market longer and prices are in terms of 1 GB is much better.