One of my favorite features of iPads is their lack of configurability. Screen size, storage, cellular, and oh, the all-important color. Done and done. Love it.
Most folks can figure out color and screen size for themselves. Cellular isn't needed if you have a good cell phone hot spot. That leaves storage. Given Apple's outrageous storage prices -- 78 cents/GB -- it is the most consequential configuration choice you have.
To put Apple's storage pricing in perspective, you can buy a high performance brand name PCIe SSD for less than 20 cents/GB -- a quarter of the Apple price. If you've noticed that the large storage iPads and Macs get the biggest discounts during sales, now you know why: they have gobs of margin to play with.
Apple's iPad storage pricing is the same across the iPad line. If you're buying an iPad Pro, choosing the next tier up might be a 15% hike. But upgrading low-end iPads? Thirty plus percent.
But what is the alternative? Easy: cloud storage. It's a fraction of the price, and, with one exception, has a minimal performance hit if your Wi-Fi is decent. The exception: if you are regularly working with gigabyte size files.
Apple's iCloud storage ranges from 24 cents/GB/year to 17 cents/GB/year. While iCloud is convenient and widely supported by iOS apps, third parties such as Dropbox -- also broadly supported -- Box, and Sync.com, are usually half of what iCloud charges.
If backup is your primary need, services such as Backblaze and Crashplan may be even more economical. The point is, before paying top dollar for Apple's internal storage, look at what you really need and explore a few options.
Now, if you're editing 4k video or large DAW files, you may need a lot of local storage. Likewise if you want a large content collection.
Even there, consider external storage that the next version (iOS 13) supports. It's much more cost effective than internal storage, and available in a lot of form factors from thumb drives to capacious hard drives and SSDs.
The Storage Bits take
Apple's iPads and iPhones are marvels of technology and mass production. I use my iPad Pro much more than my iMac, and that's not counting the hours spent on my iPad Mini 4 and iPhone X.
I also respect the fact that Apple has almost single-handedly driven consumer computing innovation for the last two decades. That's one reason I don't mind paying good money for their products.
But I have my limits, and you probably do too. Four times the retail price of acceptable alternatives is one of them. I've been very happy with Apple's minimum storage options on iOS devices, and even happier to spend the money I save on other goodies.