Fact: All 5 lb. guns, or even sub 5 lb. guns, do not handle the same. I have a 4lb. 14 oz. 28" barreled S X S that Rocketman spun for me on his MOI turntable. As he did so I commented that it surprised me that I shot it well, since I'm used to shooting much heavier guns. He commented that it was because it had almost the same numbers as a 12 ga. English game gun. It's where the weight is located on the gun that matters to handling, much more so than just the total weight.
Fact: Anyone who pays $12 a $15 a box for .410" shells is just lazy. I never pay over $8 for good 1/2 oz. factory loads, by the flat. They pattern great out of my guns. Beyond that, you can reload .410s so cheaply it is ridiculous. I do pay more for premium 3/4 oz. loads, while I am working up a good reload. But soon I will be loading .410 hunting loads, with nickel plated shot, for less than you can buy a cheap box of chilled shot 12s.
Fact: If your life is ruled by practicality you will probably never enjoy a .410. You should probably stick with $289 12 ga. pump guns. But, if you like a challenge, if you like making it a little tougher on yourself to take a limit, or run a straight at skeet, you just might find the little guns grow on you.
Fact: You don't have to pay a premium for a good .410 or 28 doublegun. I never have, and I've got 6 of them right now.
Different strokes for different folks.
SRH