[-Sneaky-]

pawn Код:

if(GetPlayerMoney(playerid) < 1000) // 1000 is the amount of cash they need
  return SendClientMessage(playerid, YOUR_COLOR, "You can not afford this."); // change YOUR_COLOR

And do:

pawn Код:

GivePlayerMoney(playerid, - 1000);

To take away $1000