Do we get any benefit from adding null check if we are already using catch all Exception handler?

This is specific to .NET I am writing a code piece where I have to use catch all exception handler. I call a series of function which may return null. I do not want to continue if any of them return null as I have an alternate but costly method to get the same result. I want to know if I should be using the series of null checks or not. My code looks something like:

    var some_info = null;
    try{
        var a = GetA();
        if(a != null){
            var b = a.GetB();
            if(b != null){
                var c = GetC(b);
                if(c != null){
                    some_info = c.GetSomeInfo();
                }
            }
        }
        catch(Exception e){
            // cant do anything here but I need above code to be silent
        }
    if(some_info == null)
        some_info = GetSomeInfoFromHeavyMethod();

in C# if we try to use null reference it throws an exception so if any of the variables above will be null a NullReferenceException will be thrown. Therefore we can write the above code like

    var some_info = null;
    try{
            var a = GetA();
            var b = a.GetB();
            var c = GetC(b);
            some_info = c.GetSomeInfo();
        }
        catch(Exception e){
            // cant do anything here but I need above code to be silent
        }
    if(some_info == null)
        some_info = GetSomeInfoFromHeavyMethod();

My question is, should I use null checks here or let exception handler work here? My gut feeling says I should use the null check as it is good practice but, I have a doubt as I have to use catch all exception handler here and I already have to bear cost of try/catch block.