Rakeback on Stake is (wager x house edge) x 0.05)
(rakeback does not change on stake, it is always 5%. however, some affiliate codes gave a higher one I think)
So it depends on the game.
If you play dice, for example, it would be:
$1000 * 0.01 * 0.05 = $0.50 of rakeback for $1000 wager of dice.
If you were playing a 94% RTP slot machine, however, it would be:
$1000 * 0.06 * 0.05 = $3 of rakeback for $1000 wager of that slot machine.