[Lenny the Cup]

That's quite a bad way of putting restrictions on players, timers should never be used for such things. Just put the time of their last action you want to block in a variable, then when they try to do it again check if X seconds passed since that timestamp.

pawn Code:

new repairtime[MAX_PLAYERS];

OnPlayerCommandText // or whatever function you're using it in
{
    // ... they try to do it:
    if(repairtime[playerid] < gettime()) // If they've waited long enough
    {
        // Do the repair
        repairtime[playerid] = gettime()+X // X = Amount of seconds you want to block them
    }
}

I would love to have some form of comparison between the CPU usage of the two different methods, but I can't think of any way to benchmark them properly.