Is that a guess? Greater demand -> better market value and greater trading volumes -> better liquidity because it requires less XRP to move x amount of money from A to B, and the market price is less likely to be affected by the move.
The majority of their XRP is in escrow contracts, so they physically can't flood the market with more than 1b a month.
$10m implementation fee, plus it attempts to make the conversion from using xCurrent (which doesn't need XRP) to xRapid (which does), the incentive being that you save more.
You might like Stellar - pretty much the same offering as XRP, but with better smart contract support and it has an open test network that anyone can use. You basically just interact via an API so you can develop in pretty much any language you like.
Swift has high fees, approx $30 per transaction, and 6% of those transactions require some sort of human intervention down the line, the last time I checked.
If you believe Ripple's marketing [1], a remittance company sending $12b of payments a year stands to save 33% on operational costs using their xCurrent software. It would also take seconds to send payments instead of days.
The majority of their XRP is in escrow contracts, so they physically can't flood the market with more than 1b a month.