[Isolated]

pawn Код:

public OnPlayerCommandText(playerid, cmdtext[])
{
    if (!strcmp("/repair", cmdtext))
    {
        if(!IsPlayerInAnyVehicle(playerid)) return SendClientMessage(playerid, 0xFFFFFFFF, "You are not in a vehicle!");
        if(!IsPlayerInRangeOfPoint(...)) return  SendClientMessage(playerid, 0xFFFFFFFF, "You must be at the repair place to repair things! loln0blord");
       if(GetPlayerMoney(playerid) <= 500) return  SendClientMessage(playerid, 0xFFFFFFFF, "You poor fuck, you can't afford this");
       RepairVehicle(GetPlayerVehicleID(playerid));
        SendClientMessage(playerid, 0xFFFFFFFF, "Your vehicle has been successfully repaired!");
       GivePlayerMoney(playerid, -500);
        return 1;
    }
}

This however, you'll want to check to ensure he even has 500$ to begin with:

pawn Код:

if(GetPlayerMoney(playerid) >= 500) {
    GivePlayerMoney(playerid, -500);
}
else { // messages }