We are talking about 2 things:

1) Earning rate for points
$1 spent = 1 point earned

2) Redeeming rate for points
100 points redeemed = $1 cashback


So in your example, it would be switched in that you want to earn 30,000 points, you must spend $30,000 (excluding 5% categories), but when you redeem 30,000 points you are getting $300 cashback.