Beyond economic repair

[ewx]

How do you decide when something is beyond economic repair? A while back I bought a rather nice lens second-hand for £400; new it would cost £690 (maybe a bit less depending how much time I spent shopping around). Since then the AF motor has failed and I've now put it in for an estimate to repair it.

My current thinking is that £200 seems a sensible limit (being half what I actually paid for it and still keeping my total expenditure less than having bought it brand new in the first place). Any other views?

Comments

[baljemmett.livejournal.com]

That sounds reasonable; when I end up with a wonky camera, I'll (intend to) have it repaired if it'll still cost less than buying a working example. My EOS RT was repaired for approximately the same as the purchase price, and although this wasn't the original plan (it was sold as working) I still paid less than I'd find one from, say, AP's advertisers. On the other hand, I haven't bothered doing anything with the EF-M because I could probably get a new one for less than the cost of repair.

[fivemack.livejournal.com]

Isn't this the sunk cost fallacy - essentially, the repair cost is a deal on a second-hand lens, and the fact that the deal involves returning your uselessish lens-shaped object is a minor detail. So the limit on the repair cost should be the most you'd be prepared to pay for a lens of this sort from eBay. And if it turns out you don't actually want the lens, if the repair costs less than that it's still worthwhile because that's the sum you'd get back selling the fixed lens on eBay.

[oldbloke.livejournal.com]

IAWTP

[armb.livejournal.com]

I think it depends on the expected future life of this one if it was repaired, of another second hand one (if you could find one), and a new one.
If you can buy another second hand lens for £400 that would be just as good as this one repaired, that's clearly an upper bound on what it makes sense to spend on a repair.
If the estimate was over £200, were you planning on doing without, or buying a replacement instead?

[ewx.livejournal.com]

Putting up with the lack of AF is a realistic option; I still get a red dot when the camera thinks it's focused and it's possible to get split focusing screens for DSLRs (handy anyway since one of my lenses is inherently MF-only).

[ewx.livejournal.com]

e.g. (http://www.katzeyeoptics.com/item--Canon-350D-Focusing-Screen--prod_350D.html). Though annoyingly no little red lights when you focus - so it's not a great all-round solution...

[new-brunette.livejournal.com]

Which lens is it?

[ewx.livejournal.com]

I thought someone would ask l-) 135mm f/2L.

[new-brunette.livejournal.com]

Ouch. I'd have been very tempted to leave a macro lens as MF-only but not that beaut. I think the price you'd be prepared to spend on it to repair also depends on whether you could afford to make the purchase afresh now. So how much would you sell it for in broken state?

[gjm11.livejournal.com]

(I'm really saying the same as some other people have, but being a bit more tediously systematic about it.)

Options:

1. Keep using the lens. You have: MF-only lens, no change in money.
2. Buy another one. You have: MF-only lens, AF-capable lens, X less money.
3. Get it fixed. You have: AF-capable lens, Y less money.
4. Sell it. You have: no lens, Z more money.
5. Get it fixed and then sell it. You have: no lens, W-Y more money.

So, the key questions are (1) what are W,X,Y,Z? and (2) what's the value to you of (a) the lens without AF, (b) the lens with AF, and (c) the lens with AF and a backup without AF?

It seems like X is probably about £400. You're in the process of finding out what Y is. Presumably W is slightly less than X. Z is probably quite small and I'd guess that W-Y is bigger. As for question 2, only you can answer it, though if your finances haven't changed much it's reasonable to guess that the answer to (b) is somewhat more than £400.

After that, it's just arithmetic :-). Questions like "how does my total expenditure compare with having bought it new?" and "is this more or less than half what I originally paid?" seem entirely irrelevant, except in so far as they help determine your psychological state after making whatever decision you do.

[songster.livejournal.com]

This is a simple optimisation problem. Ignore the sunk costs completely, what matters is how much you actually get for your money. If you can get it repaired and have it be as good as new, then anything up to £689.99 still means you come off better on the deal. If a repaired version will only last half as long as a new lens, then as long as you pay less than £345, you're OK.

You have two parameters - the cost to get a fully functioning lens, and the expected lifetime of said lens. Your options are:

1) Repair the existing lens. Cost = x, expected subsequent lifetime until breakage = y

2) Buy a new lens. Cost = £690, expected subsequent lifetime until failure = z.

Go for whichever is the smaller out of (x * y) or (£690 * z). If you like, you could add a third option:

3) Buy another second-hand lens. Cost = £400 (?), subsequent lifetime until failure = a. You can estimate a as being "a while", since that's how long the last one lasted.