My Ipad 1 is the $30/month AT&T grandfathered unlimited and upgraded to the Ipad 4 32gig LTE and still $30/mo unlimited.
...
I can afford to buy it with no problems.
I can also sell my Ipad for quite a bit on the brazilian black market if I upgrade again. See no need this year though. Don't know anyone who upgrades every time unless they can sell it for a good price I guess.
I can resell my iPads in China for good prices, too. I don't bother, though. Between my husband and me, we've given away three of our older iPads and still have a couple newer ones. We get to enjoy later models, and we spread the fun to others with the older models.
I've enjoyed AT&T unlimited since day one of iPad 1's 3G model and am still loving it. I plan to keep it till they cut me off, lol.
For me, owning lots of devices is a treat. I don't see need to justify my uses or enjoyment to anyone else unless they care to pay all my expenses, lol.
I find that when other people try to mind other people's spending, it's usually a case of sour grapes, or of them not having enough money of their own to mind, lol.