WHAT DOES BERETTA ARX100 FOR SALE MEAN?

I even spoke with the Beretta rep, Alex Koines, when he had the Beretta products demonstration trailer at Four Seasons two weeks ago and he experienced no great suggestions. Several "smiths" at diverse gun outlets in the region said they could drive off then set up the new rear sight for $40 using a hammer and brass rod. If I don't find a sight pus