I rarely have a issue justifying moderate hardware upgrades. For me it is a hobby and far cheaper than the thousands I used to spend racing motorcycles. Plus I sell my old hardware or trade out my son's computer or the HTPC if I feel inclined. For instance I sold my year and a half old i5-750 and motherboard for $210 and got my new i5-2500k and Z68 motherboard for $360+. $150 out of pocket is not cheap by any means, but I spend $160/mo on my cable bill and I get far more entertainment out of my computer. In 6-18 months I will upgrade again depending on if the itch is great enough or not. So my justification is the enjoyment I get from building/messing with new hardware and the extra performance, even if it is not a giant leap, is just the icing on the cake.
Yeah, you can't discount the hobby-with-curiosity factor.
There was a time when I'd squeeze three to five years out of every new machine, keep the old ones for a while on a LAN. Now I have more than I need, and pass them on as hand-me-downs to the fam-damn-ily.
Also in those times of squeezing blood from stones, I was teaching programming in a Comp-Sci/Info-sys program to foreign grad students. My department chair once said "you can afford to build a new computer every year . . . . " But I never actually did that on a regular basis as I review the statistical time-series of builds I did for myself.
This time around, while I'd reasoned that my Q6600@3.0 Ghz would do for a few more years, there were two things in the back of my mind I might have analyzed more carefully: I HATE the motherboard, and there had been a glitch with Media Center causing occasional random crashes. It occurred infrequently enough that my efforts to cure it -- while ongoing -- lacked panic and urgency.
Now that I've ordered the parts and built the new Z68/i7-2600K, I thought I might at least have postponed for at least three more months.
And while playing "musical computer repairs" with my Bro's machine, the new build and my Q6600, I think I've found the problem with the glitch. Which I had to do anyway, if I were to pass it on to Bro in about four months.
But in the current economic times, your hobbies may give you pause as you think about being prepared for . . . whatever. . . .
Not too bad, though. I'm just a bit weary of living in a room where I need to step carefully around computers, cases, parts -- like Burt Munro of "The World's Fastest Indian," living and sleeping in a one-room motorcycle garage with a pot-belly stove used to forge experimental pistons . . .
If a grown-up occasionally feels like the four-year-old sauntering down the street with a big Hershey-bar and chocolate drooling down his chin, I suppose the computers are better than the Hershey bar. Which reminds me . . . . . I haven't had one in SOOO long! I think I'll count some pennies to prepare for the next gas-conserving grocery-run . . . .