Computers:
I bought a laptop in 2009 ($1500, work paid half) and one in 2015 ($700 including an external cd rom). I received a gift old (~4 yrs at the time) laptop a family member was replacing in 2007, and a gifted newish one in 2004 that I heavily used in law school. So apparently one every 6 years, but I'm moving towards cheaper and faster replacement so about the same annual cost.
DH bought a laptop in 2009 ($500) that died in 2013 and an Ipad in 2013 ($200).
Phone:
I bought a iphone in 2011? ($200). Will replace this year if they ever come out with a smaller iphone size again.
DH still uses a phone of average intelligence from ~2008. ($50)
Kindle:
Gift in 2012 ($70) but I'll replace it when it dies so I'll include it.
External hard drives:
Bought two ($50 each) in 2015 so we can back up the back up (we care about our photos and almost lost them when the prior external hard drive from 2007 died).
2014 Cable replacements (saved us well more than they cost):
Roku: $90
Mohu Leaf: $50
Cromecast: $35
TV:
Mine is 2007, DH's 2007/2008, just before we met each other. $700? for mine.
DVD player:
Mine is 2007. Maybe $100? Not sure on DH's age or cost.
One of the two broke 6 mos ago. We haven't and won't replace it.
Stereo:
No idea age or cost. [At least 10 years, likely 15-20 years old. Doubt we'd replace.]
Router/modem:
We need to buy a new router/modem. Mine from 2007 ($100) are terrible.
Printer:
Own a gifted one (2012) that doesn't really work.
Digital camera:
$500?? in 2007.
Essentially, I bought a lot of tech stuff when I graduated from law school and got a place on my own w/o roommates or boyfriends. We have some duplicates bc we met later in life and the doubles haven't all died (but we won't replace).
That's $675/year, except I anticipate the Kindle, Roku, Mohu Leaf, Chromecast (all newish purchases for which I don't have a longevity baseline) will last at least 5+ more years. If I assume 7 years for each of those, it's $515/year. It'll drops to $485/year when you consider the tv is likely to last at least 4 more years and $468/year when you figure we'd buy a cheaper one next time around. So - maybe $450/year, as I'm not going out and replacing my DVD player or camera today either, and DH's switched to a cheaper tablet from a laptop which is also not dying today?
I don't budget a specific tech budget. We get things when they die usually. Rarely do we bother to get ahead of the curve and buy things before they die, although we are going to start trying that with laptops.
Interesting to calculate though.
[ETA: Forget our noise cancelling headphones bought last fall. $250 and $300. Probably ups to ~$515/year]