Welcome Andy.
Originally posted by AndyPanda45 I'm hoping someone can point me in the direction of a good, basic Pentax DSLR camera that will accept those lenses (SMC Pentax-M 50mm, Vivitar 28mm wide-angle, Tokina SZ-X 35-70mm, and Vivitar 70-150mm close focusing auto zoom) without costing me half my pension!!
One of the great things about Pentax is that they have stuck with the K-mount since the mid-1970s. I used to have a Canon SLR with FD mount lenses. When Canon turned its back on that mount tens of thousands of FD lenses more or less became paperweights.
All of your lenses will work with any Pentax DSLR with an APS-C sensor. They will also work on the mirrorless K-01 (which also uses an APS-C sensor).
With an adapter, K mount lens can also be used with the mirrorless Pentax Q cameras (smaller sensor) and with the medium format 645 cameras (larger sensor) but unless you have a special reason to do so, don't worry about them.
All the Pentax DSLR cameras allow manual exposure readings for manual aperture lenses like the Pentax M series. Pentax APS-C cameras from the K10D and K200 onwards have a dedicated button (the green button) that makes this easier. (Instructions on using the green button are here:
http://support.us.ricoh-imaging.com/node/3 ) For that reason alone I would suggest you look at one of those models.
For a list of Pentax DSLR models and a summary of their features, see here:
https://www.pentaxforums.com/forums/pentax-cameras-compared
All Pentax DSLRs from the K100 onwards have image stabilization in the camera. That means you can use a slower shutter speed without incurring blur than would otherwise be the case.
Have a look in the marketplace on this site or sites like KEH or Adorama and you will find out the rough prices of each model on the secondhand market.
I'd say first work out which features and specs matter the most to you. For example, the sensor pixel count ranges from 6 megapixels for the *ist and K100 to 24 megapixels for the K-3. Cameras from about the K-20 (?) onwards can take videos as well as still photos. Recent models let you take pictures in jpg and RAW format at the same time. And so on.
Once you have worked out your minimum requirements, look for the most recent camera with those specs and features that you can afford. Each model generally added more features than the one it replaced.
If you have a particular budget in mind, ask here and you will get lots of suggestions!
My comment is that recently superceded models are generally excellent value. For example the price of the K-5IIs and K-30 has dropped since they were replaced by the K-3 and K-50 respectively. But even if you only want to spend less than say $150 or $200, you can still get a very good camera.
When I switched to digital in 2007 after 25 years of film cameras, there was a bit of a learning curve. But mainly I was astonished at what the digital camera could do.