Don't get me wrong I really like the Pentax cameras and the lenses are top notch, but I just cannot advice anyone to buy a Pentax dslr. They are not really any cheaper when all said and no critical or novel features.
I think your idea on what equipment dslr owners buy and the life of lenses is some what warped. I am using a couple year old lens design and I will be gutted if some of my new lenses don't last 10 years. I have gone through 2 camera bodies in the last 8 years and I will probably buy a D800 this year that I hope will last 5-6 years.
I am not sure what you are going about TBH,about price?? I looked at the Pentax K5 and a 16-50MM/F2.8 and it was around £1230. The Nikon D7000 and a 17-55MM/F2.8 comes to around £1830. The K30 has most of the features of the K5,with a polycarbonate body with a stainless steel frame and is even cheaper.
You talk about lack of novel features -like a pentaprism and weather proofing at £500 to £600??
I own a DSLR myself and kept my old
film lenses for years but again this is the issue with many people on forums or in photography clubs who have an inability to relate to the wider market. However,I am also know I am not typical of most of the dSLR market at all if I look at the whole planet.
Many users have not moved from film SLRs.
If you go on this forum you would think all PC gamers the world over would be having a Core i5 2500K at 4GHZ+ with £200+ GPUs. However,that is not the reality of most PC gamers,is it? The same goes with computer users - most have laptops or tablets not desktops(this is supported by sales figures and the way OSes are heading) and even most desktops are prebuilt. Yet,on computer forums a large percentage have a desktop and most will assemble them too. They will also have a greater tendency to upgrade the parts too.
You don't realise most DSLR owners are not pros,hardware enthusiasts or sell their work or display them on forums or galleries. This has been the case for decades.
Remember this is a £500 to £600 camera not a D800 which costs many times that. Its not even the price of a D7000.
This camera is not for you though - it is not your target market.
We are on a forum where many like minded people aggregate together,but don't think this is indicate of the majority of dSLR purchasers.
I have known enough photographers from pros to the average person and don't think most DSLR purchasing is limited to advanced amateurs and pros.
If anything that is far from it. The mindsets are very different between each group,why they buy a product and that is after actually listening to their purchasing reasons.
You talk about warped - how many people will buy a D800 as a percentage of Nikon DSLR sales?? I have known people who were pros in the 1960s with Nikon F(the first one) and Rollei medium format cameras - so don't think I have have no clue what different photography markets are like.
By that very admission,you are small percentage of the whole DSLR market,so in that sense you ideas could be warped about the majority of the dSLR market too,especially if you came from film.
I also have done other imaging work too - so I also have a very good understanding of the basic technology and have used equipment from Olympus,Leica,Zeiss and Nikon which would make a medium format digital camera look like pocket change.
What percentage of dSLR users will buy APS-C frame lenses only? What percentage will buy 35MM frame lenses and what 35MM frame lenses will most buy?
How many of the lens purchasing decisions are determined by cost or weight for example??
How many will just buy a kit package and still use it years later?? How many will buy a Sigma or Tamron lens because it is cheaper??
We are not talking about D700 or D800 level cameras which are well over £1000+ but £500 to £600 cameras.
Even then how many are thinking - I might get a camera with a 35MM frame sized sensor in the future?
You could make an argument for macros,but even Nikon makes a DX macro.
Even then with product segmentation,you tend to find the cheaper models might not function entirely properly with the older 35MM legacy AF lenses,since they need an AF motor in the body,or lack support for newer metering improvements and other things.
In the film days it did not matter. You could buy a cheaper body and then spend more on the lens. It was not uncommon.
Eventually you could get a more expensive body. This is not the case anymore - most FX lenses are not AF-S and those that are expensive or there are just better DX alternatives available.
The whole D3000 and D5000 ranges lack an AF motor and the D90 which does,is from 2008. There is a good possbility that the D90 won't have an actual replacement from what I gather and Nikon will slot in a more expensive D5100 replacement instead,which probably lacks an AF motor too.
In fact Sony is one of the few companies which seems to mantain legacy support with their dSLRS(even with the cheapest cameras) so people can still use their old Minolta lenses even from the 1980s. However,I even see that changing as I doubt many people would care anymore.
Even with the D7000 coming to the end of its life it is still around £770 to £800 with cashback and the new model will probably be closer to £1000 at launch just like the D7000 was.
Nikon themselves do just under 20 DX lenses - I have a slight feeling that these probably are the highest sellers. I also would think Nikon DX sales are pretty large too.