Those are: casino model, door security and vault door. So my question is, I've to buy them er'time I do the heist or is one time buy and I'll have it in every set up I do?

Diamond Casino Heist Payout: $10.34 -R$11.37 Million\n\n The Diamond Casino Heist payout is by far the highest in GTA Online. The rewards for the mission add up toR$10.34 million on normal difficulty, and it can go up toR$11.37 million, if the heist is on hard difficulty.