For now what I'm doing is buying in the same caliber . I love to shoot and having to buy many different cals to go shooting sucks . So right now Im only buying 308 , 9mm , 22 , and 12ga guns . If a SS marlin 30-30 comes along I will get it but for now Im sticking with the same calibers I already have .
I just bought another 308 bolt gun and im looking for a 308 semi as well . If a good 9mm carbine comes along I"ll grab that up as well .
Back to your original question . You can never have to many ARs . I have a few and still want more as long as they have a purpose different from the ones I aready have . I don't want two that are the same .