Staff note: This post may contain affiliate links, which means Pentax Forums may earn a small commission if a visitor clicks through and makes a purchase. If you would like to support the forum directly, you may also make a donation here.

---

There's a Pentax-A 100mm ƒ/2.8 on the bay right now for 666.66 obo. The price is pretty high compared to the average price you see in the lens review database. I got mine from a guy trying to get rid of his ME Super outfit quickly, so I got it for less than I expected to pay ($150~). It looks like all of the other folks in the review database did too: $50 on Craigslist, $25 from a pawnshop, etc. Even still I read it has a reputation as a stellar portrait lens (which is why I bought it in the first place).

So…what is the going rate for such a lens? I'm sure $666 is too much and too evil , but what is it worth to people?

[dadipentak]

$666.66

The seller is Satan?

[LennyBloke]

Probably the most under-rated Pentax portrait prime produced

[rbefly]

That's pretty steep!
I agree with dcshooter, the lens prices on the reviews often don't reflect real-world selling prices, because of the factors mentioned.
I've been keeping track of the price trend for the smc A 135mm f/2.8 (not the same FL, I know, but same series and roughly comparable) since I mentioned it on another thread. Several people seemed surprised that I paid over $200 for mine, but I had been outbid at $200 for the two previous offerings. That was nearly two years ago, the latest one I saw recently went for $270. The 135mm f/2.8 may not be quite as rare as the 100mm f/2.8, but I only found 3 biddable (is that a word? Clean, good photos of the lens, bayonet, 'see through' photos, etc) copies in a year of looking. If the A135mm f/2.8 is rare, the A100 is nearly extinct.
A couple of possibilities here. The smc A 100mm f/2.8 MACRO has a 'Lens Review' price of $ 600. Not a likely mistake, but could happen.
It's in such fine shape and hard to find, he's aiming high to get as much $$ as possible.
I don't know if they'll get the asking price, but $350-$400 might happen. If you've got one, hang on to it!
JMO
Ron

[Trigger Happy]

They can ask whatever they want. Doesn't mean they're going to get it.

Sometimes items listed as Buy It Now "OBO" have ridiculously high prices since they expect people to make an offer. This particular listing was ended so it's not clear if that was the case.

[vonBaloney]

I would expect the A100/2.8 to go for more then $200, but $300 is pushing it. (The last one on ebay in decent condition sold for $230, although from Thailand. Another one with fungus sold for $100.) Of course if someone wants to give me $666 for mine, I'm listening. ASKING prices on ebay mean nothing -- look for the actual sales.

And yes, please don't base your decisions on the prices in the review section, at least not without carefully examining the dates and other clues. But really, they don't mean much. Look at ebay, KEH, etc. (For the ones that SOLD only.) Or just ask here...

[Tako Kichi]

The price could also have been a typo which could explain it being ended. It may come back up again with a more realistic price at some point.

[MJL]

I owned this great lens >20 years on SLRs and love every mm of it. I sold it on the Marketplace for ~$300 because I use it mainly indoor and the dark dSLR viewfinders make it very difficult for me to manually focus. Presently I am using a faster/brighter MF ZK 100/2 Marko for closeup and an AF Nikon 55/2.8 for 1:1, but I would say the A 100/2.8 IQ match these 2 razor-sharp lenses.

[keyofnight]

Cool. Thanks for the points of reference folks. The lens is so rare that I don't see many completed/sold listings on the bay, and even those look strange: this one, for example, only got two bids. I guess you're right, LennyBloke: the A100 is quite underrated. It seems like people are more willing to pay top dollar for the "macro" version of this lens, but I don't even see those on Ebay very much. I'll just have to go with you guys and say it's worth anywhere between $200-$400. (:

I will hold onto mine as long as possible, rbefly. It's probably the sharpest lens I own.

It's a shame you had to sell your lens, MJL. Wait…are you saying that you replaced the A100ƒ/2.8 with a $1800 Zeiss lens? Wow. The two are comparable?

Hey dcshooter, I agree about the marketplace prices—they're not a very good indicator of real world prices for all of the reasons you mentioned. Also, I knew Jobs and Wozniak sold their soul to get Apple off the ground, but this is a little much!

[monochrome]

Late addition - K105/2.8 is around $259 and the hood is $49, so $666 is high but not necessarily ridiculous.

[tzrenz0]

That's pretty steep!
I agree with dcshooter, the lens prices on the reviews often don't reflect real-world selling prices, because of the factors mentioned.
I've been keeping track of the price trend for the smc A 135mm f/2.8 (not the same FL, I know, but same series and roughly comparable) since I mentioned it on another thread. Several people seemed surprised that I paid over $200 for mine, but I had been outbid at $200 for the two previous offerings. That was nearly two years ago, the latest one I saw recently went for $270. The 135mm f/2.8 may not be quite as rare as the 100mm f/2.8, but I only found 3 biddable (is that a word? Clean, good photos of the lens, bayonet, 'see through' photos, etc) copies in a year of looking. If the A135mm f/2.8 is rare, the A100 is nearly extinct.
A couple of possibilities here. The smc A 100mm f/2.8 MACRO has a 'Lens Review' price of $ 600. Not a likely mistake, but could happen.
It's in such fine shape and hard to find, he's aiming high to get as much $$ as possible.
I don't know if they'll get the asking price, but $350-$400 might happen. If you've got one, hang on to it!
JMO
Ron

I got the A 135mm f/2.8 last week from adorama I paid U$D 99 and 59 shipping I don't really care about shipping, but if I was a bit luckier and living in the US that would be less or free as well. Lens condition is E+ this is the first time I used adorama so I've no idea how faithful their ratings are.

[tzrenz0]

Oh just an after thought I've seen a couple on Keh this year, last sighting was last month it was gone in minutes can't even remember the price now.

[zbrueningsen]

The A 135 and the A 100 are not in the same category. I had the M 100 2.8 and it was much better than the 135. I found it to be much better than the overrated, but beautiful 85 f/2. I almost bought that A 100 2.8 that had fungus. Mine had a little bit and it was still contrasty and sharp. This lens is made to be shot wide open.

[keyofnight]

The A 135 and the A 100 are not in the same category. I had the M 100 2.8 and it was much better than the 135. I found it to be much better than the overrated, but beautiful 85 f/2. I almost bought that A 100 2.8 that had fungus. Mine had a little bit and it was still contrasty and sharp. This lens is made to be shot wide open.

Well, how much would you pay for an A100mmƒ/2.8 in, say, "very good" condition? Also, would you say the M100mmƒ/2.8 and the A100mmƒ/2.8 have the same optical formula?

[aurele]

Also, would you say the M100mmƒ/2.8 and the A100mmƒ/2.8 have the same optical formula?

yes they have the same formula : 5 elements in 5 groups.


formula not far from the one of the M/A 50mm f2