Morning Barney, and welcome to the Forum!
I think that you are approaching this in the right way. After using your camera for a while, and finding what you want to do, then add items where your interests lie.
I do think that the Tamron suggestion has a lot of merit for the price and the focal length range. I had the Pentax FAJ 75-300 which was fine but their 55-300 is much better. This link compares the Tamron to the FAJ and I think that you would be happier with the Tamron, especially with the macro capability. Personally, I like the range to 300 better than 200 because of the additional reach. My feeling is if you initially go with a 200 or so, in time you will just switch to 300.
https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/8582-tamron-70...-75-300-a.html
On your overall question, I think that you need to answer if manual focusing is of interest. If so, as others have written, there are a world of great manual (both focusing and aperture) lenses out there available for very reasonable prices (even if you have to buy the film body that is attached to the lens). I would prowl the marketplace here, evilbay and KEH for used lenses. Be very patient, and you will find what you are looking for at your price range.