You can either buy it with nether stars in the star shop or from other players. It costs 1500 nether stars in the shop if you were to buy it directly. Nether stars generally sell for about $500 I believe. If you wanted to buy one directly from a player, it would cost you anywhere between $600,000 (upfront payment, seller is low on time) to probably $900,000 (payment plan). Good luck!
I bought one on payment plan(450k down) for a total of 650k. Don't pay over this, they're not worth it.
