I live in Arkansas, and my AT&T bill this month is $410. Granted, about $150 of that are payment plans for devices, but still. The base rate plan is $110, and there's a $20-30 per line fee for four separate lines.
I have an iPad Pro 11" LTE and an iPhone X, my wife has an S10+, and I handed down my 6th Gen iPad LTE to my 10-year-old. It's a lot more than "needed", and our aggregate data usage is 30+ GB/month, but still. The difference in cost is staggering.
The $130 extra for an iPad with cellular and $20 extra per month for unlimited data on the iPad is well worth the convenience of having two cellular devices.
I pay roughly $210 a month for five phones and two iPads all with unlimited data.
T-mobile also has free data roaming in most other countries where we go on vacation.
Finally, I very often tether my MBP to my iPad, because the iPad's battery lasts much longer. If my phone battery is low I pretty much need to charge it so I can get calls from family. If my iPad's battery dies I'm merely inconvenienced for a while.
Bit lower than your $410, but it sounds like you have multiple plans, always buying very high-end new hardware. There's a point where you have to accept that this is an expensive hobby or luxury item. You chose to get all these devices.
Oh, no doubt. I'm not really complaining about the price I'm paying for the devices themselves; I included that specifically so it wouldn't be taken as if the entire bill was due to the data I consume.
> always buying very high-end new hardware
That's a pretty recent thing for me. The first new flagship phone I ever bought was an S7 Edge. I liked it enough that it made sense for me to upgrade to the iPhone X when it died. The 6th Gen iPad was an impulse purchase, but one that turned out to be a much more practical thing than I expected. Then I upgraded and passed it down to my daughter - she's homeschooled, and can access her online lessons from wherever we happen to be on it, which is very handy.