A few things to help out with Hive-Engine transactions:
The price listed on the VOUCHER page of Hive-Engine is in HIVE, so a purchase price of 1.645 for one VOUCHER is actually about $2.50 because HIVE has been trading around $1.50 each (1.645*1.5 = $2.4675)
A much simpler (and cheaper) way to get your money to Hive-Engine is to purchase a top-tier coin like Bitcoin (in Coinbase is where I do it) and then use SimpleSwap.io to send it to your Hive wallet.
Move it to Hive-Engine (or Leodex.io if you want to save some fees).
RE: Getting Vouchers in the US