I don't think so. You do well on your phone, and if you need to print something many library's have free use of computers and minimal charge for printing. (some even let you print for free). It depends totally on how much you use the computer and what you use it for.
It seems every household is required to have a home computer, yet people like myself cannot afford it. Are we going to be lost in time due to this?
It's pretty much a basic necessity at this point. But for the elderly person that's not too big into technology or have hobbies relating to it (My 70 year old grandpa is a pro at Autocad), a mini netbook is really all you need.
https://www.google.com/chromebook/find/
There's many options. You can get a Chromebox and then pick up a dusty monitor at Good Will or Savers for 5 bucks. A light netbook to write stuff and browse the web. Or just a tablet.
Last year was the release of the Raspberry PI. The worlds first $5 computer.
http://abcnews.go.com/Technology/raspberry-pi-computer/story?id=35432176
Go to Shopgoodwill.com. You can get a very decent laptop there for under $100. (It won't be the latest and greatest, but that's probably not what you would expect anyway.) You just have to be patient, follow the auctions, and have a small amount of luck.
If you are just checking e-mail and surfing the web, you can probably get away with a tablet. I would switch to tablet if I didn't use my computer for photography. You can pick up a new off brand for about $50. Name brands go for $100-$200.
Check out your local Freecycle and/or Craigslist/free listing. I see computers on there every once in a while.