Good Morning,
It looks like you hit the mother load of lens auctions. Congratulations!!! From reading the thread, it looks like you would like to recoup your initial investment, while keeping what you are and / or might be interested in over time. The comments you have received as others have said, are good opinions. Most everyone would have loved to score a haul such as this - with some of the best lenses Pentax has available.
That said, there are so many ways you could slice and dice this, its really impossible to know how to approach this with out knowing what you like shooting. For instance .....
- Landscapes - If you like landscapes, you want wide, however you would not really need fast. f4 would certainly be fast enough, thus you could keep the 12-24 and possibly the 16-45, letting the faster f2.8 lenses go - 16-50. Also the second kit lens would probably be the first to go - instantly, as you really do not need two. You might even consider selling both kit lenses, since depending on what you decide to keep.
- Changing & hauling lenses - if you dislike changing lenses or if you just want a single lens kit for travel and vacation, the 18-250 would be a keeper.
- Low light - if your focus is to have low light lenses, then you have the core here, at least in zooms. Thus, you would keep the 16-50 and 50-135, selling the 16-45 and kit lenses. The 70 and 100 Macro would be keepers here also, along with the 50/f1.4. But you already indicated that you could part with it, if you were able to acquire another less expensive f1.7 or something along those lines.
- Primes - if your interests range to primes, then the 70 and 100 are keepers. However, this is only the start, so you would want to acquire other in the focal lengths of interest, which would force you to sell the other zooms.
- Image Quality - If you are into increased image quality - well you really have a problem, as most all of these would be keepers. Both of the kit 18-55s could go along with the 18-250.
- Portraits - Keep the 50, 70 and 100, sell the wide angles - 12-24 and 16-45 along with maybe the 16-50. The 50-135 would be a keeper, however that duplicates the ranges of the primes.
- Physical Size - Large vs Small - Sell the large heavy ones, keeping the small light ones.
- Telephotos - If you are in to the longer range, then sell the short range - 12-24, 16-45 and 16-50 along with one of the kit lenses.
- Screw Drive vs SDM - If you are looking for simplicity and longevity in your lenses, then sell the SDM lenses and keep the simpler ones.
The Sigma TC is the odd one here. If you do not need to boost your focal lengths, and if it does not operate with any of the lenses, that would be an easy candidate to go.
The K10 body I believe has really plateaued in price in the mid $300. With the low shutter count, there will always be folks interested in one. Other than the new K5, it's the only body that you can turn off dark frame subtraction on so folks looking to do Astrophotography would be interested. I would tend to sell it, so as to keep more glass. Plus, the Kx is not a bad camera at all.
It all comes down to what you are interested in, thus keeping. If you do not have an interest, then I see it going - even if its a great lens. Also, it would appear to be dependent on the price that you purchased the lot for.
For selling, I would also consider the Market Place over on the Pentax Forums. If you do not get your price there then off to evilbay.
What would I do? Gee - that is really a difficult problem...
- Keep - 12-24, 16-45, 50-135, 70. This would keep the quality and sell the items that may exhibit problems, plus I am not that interested in Macro (just me). I also have a 50/1.7 and do not use it all that much, so I could let the 50/1.4 go. Also, I am not into flashes. I might even be able to sell either of the 50-300 or the 250 (maybe even both), in order to keep some of the above lenses. But - that is just me.
- Sell - both kit lenses, 16-50, 100, 18-250, 50, Sigma TC, K10, the flash.
You problem is the problem everyone wishes that they had...
