About a decade or so ago, I purchased a Pentax K2 for a now former girlfriend along with the 50mm F/1.4 lens. Since my Leica M-4 was accidentally dropped from tripod height along with the 135mm Hektor F/4.5 lens mounted on the Bellows II which was mounted on a Visoflex III, which was mounted on the camera body - there was a lot of kinetic energy/weight when the tripod accidentally fell to the concrete sidewalk.
Being a relatively poor former Graduate Student at the time, (I had just graduated with a degree in Library Science), I didn't have the funds available for the repair of my beloved Leica M-4 body.
So I "borrowed" the camera and the lens back and have been slowly adding to my Pentax K2 collection since. Currently, I am only "missing" a 35mm F/2.0 lens, which I will one day add. I believe this lens is somewhat rarer than the K2 body. Although my former girlfriend and I separated, but still remain friends, this camera and its wide array of Pentax lenses will be inherited by my daughter sometime in the near future.
In my decade plus years of experience, I have found that the K2 is worth more than it's weight in gold, has been extremely reliable and will produce quite excellent images - in short, I believe that it is a good and wise investment for many people who want to practice good 35mm photography with more than decent photographic equipment. By the way, I have always thought that the ME series and subsequent models were "tinnier" than the K2, etc. models.
Having said that, I must also point out that the quality of Pentax cameras and lenses, along with many other camera manufacturers, do not come near the image and mechanical quality of Leica cameras, lenses, projectors, and enlargers! Period!
If you wish to obtain more information about the K2 model, I would suggest that you read and/or obtain a copy of The (Honeywell) Pentax Way by Herbert Keppler. You'll have to find the edition which includes this and the other K models i.e. K2, KX and KM. At search at or through your public library and/or a search at either abe.com or alibris.com should prove fruitful. Probably, you'll end up looking at an early 1980's edition.
If you are fortunate to live near a larger city or do some traveling now and then, you might explore camera shops in the neigborhood and see might be available.
If you come across a used K2 body, open up the back and smell the back end of the camera. Smell? Yep, it will give you an indication as to whether there might be mildew and/or rust present; run the shutter speeds through a range of speeds while holding the camera up to your ear as it will give you an indication as to whether some CLA (Cleaning, Lubrication, and Adjustment) needs to be done. Listen to the gears when you advance the film as it will give the same indication, etc.
If you make a purchase through Ebay, make certain that the camera is in excellent to near mint or mint minus condition and see if the camera is under some kind of guarantee. When the camera arrives, check it out through the above method and then make your decision.
I suspect that all cameras of this vintage would be in need of a basic CLA to better insure that you will be using it for the next many years to be prepared to spend a little extra money to maintain the camera.
Hope this is useful.
Bill