It definitely is $10 of coin-in per point on Video Poker and I think (but I don't know for sure) that it's $5 of coin-in per point on Slots.
So that would make it $500 of coin-in played through to get $5 in Freeplay if it's done with Video Poker whereas with Slots, it may very well take $250 of coin-in played through to get to the $5 of Freeplay.
RecVPPlayer