Interesting discussion. I recently bought a good second hand K10d with very low shutter count. My original intent was to gift it to my niece, as she is getting into photography, but alas she prefers mirrorless... which is another story.
Anyway, I kept the K10d and have ended up using it quite a lot. Originally I kept it intending it to simply be a backup because as a largely ignorant neophyte I assumed that a six-year old 10Mp camera couldn't bring anything to the table next to a K5. Well, that changed when I read on here some people's experience with the K10d and the peculiarities of it's sensor. It turns out that so long as you can keep the ISO low, the CCD sensor has a weak anti- aliasing filter and so it is actually quite sweet with a prime and even light (eg: such as outdoors in overcast conditions, just when you need to keep your weatherproof lens on your weatherproof camera). So, on one shoot I left my DFA100 on the K10d and took my portraits with it... and it was actually really great. The trick is not to be fooled by the little display on the back, the lack of mod-cons and to remember to adjust exposure compensation to suit the conditions. Certainly, if you don't mind a camera that is a bit less forgiving and will make you think a bit more, a K10d will be a worthy challenge rather than an inconvenience. Get the pictures printed or up on a decent screen and you can see why this camera is such a stalwart. Add great build quality, ease of us and weather sealing and you have an excellent camera for the price.
Bottom line is that when I checked out some of the great images on this site produced by skilled photographers using the K10d, it was plain the limiting factor for me is still the operator rather than the kit
. If you can get a good copy for a reasonable price, I reckon the K10d will do as a great second camera, especially if you need the weather sealing.