[GRiMMREAPER]

I have my sincere doubts you've read sscanf's documentation, therefore do it before you post your doubts here.

Regardless, try this code. You had a variable named "string" for no reason and you were using strcmp wrong. Give this a try and let me hear back from you.

pawn Code:

CMD:selldrugs(playerid, params[]) {
    if (Player[playerid][Job] != JOB_DRUG_DEALER) return SendClientMessage(playerid, COLOR_RED, "* You must be a drug dealer to sell drugs.");
    if(gTeam[playerid] == TEAM_COP) return SendClientMessage(playerid, COLOR_RED, "* Law Enforcement officers can't sell drugs.");

    new amount,
        type[30];

    if(sscanf(params, "s[30]i", type, amount)) return SendClientMessage(playerid, COLOR_RED, "* [USAGE]: /selldrugs [drug type (marijuana, cocaine)] [grams amount] | Ex: /selldrugs marijuana 50");
    if(amount < 1 || amount > 50) return SendClientMessage(playerid, COLOR_RED, "* Min amount: 1 gram | Max amount: 50 grams.");

    if(!strcmp(type, "marijuana", true)) {
        if (Player[playerid][MarijuanaGrams] < 0) return SendClientMessage(playerid, COLOR_RED, "* You dont have marijuana to sell.");

        Player[playerid][MarijuanaGrams] -= amount;
        GivePlayerMoney(playerid, MARIJUANA_COST_PER_GRAM*amount);
        SetPVarInt(playerid,"CmdTime",GetTickCount()+5000);
    }

    else if(!strcmp(type, "cocaine", true)) {
        if (Player[playerid][CocaineGrams] < 0) return SendClientMessage(playerid, COLOR_RED, "* You dont have cocaine to sell.");

        Player[playerid][CocaineGrams] -= amount;
        GivePlayerMoney(playerid, COCAINE_COST_PER_GRAM*amount);
        SetPVarInt(playerid,"CmdTime",GetTickCount()+5000);
    }

    return 1;
}