Originally posted by zapp If you are looking for a second hand priced FF system, Pentax is not what you want - unless you can wait for the K1 to be replaced/upgraded.
If you are looking for a well priced new FF system, Pentax is a very good choice.
I don't agree at all for the new FF system. Many lenses are not there at all or from Sigma/Tamron, the older version as the new ones are not available at all.
Pentax has only expensive high end lenses available new even the 28-105 is not cheap just a bit cheaper than say the Canon 24-105 f/4 I... The affordable FF primes available new are restricted to FA35 & FA50. There no cheap 70-300 outside the older versions of sigma/tamron... The new f/2.8 primes for Pentax are extremely expensive and for some just rebadged tamron you can get at better price in Canikon.
If you go for Pentax FF you should go there because you love the brand and the specifities offered like pixel shift, astro tracer and other things like that. You'll not save money there if you are not already heavily invested in K-mount.
If you want small light, that more like Sony if you know what you are doing. If you want nicely priced AF lenses and lot of choice, that's Canon. If you want the best AF for action/sports that Nikon. If you want to play with MF lenses from any manufacturer and a great experience when focussing manually that Sony again.
Pentax is a small player that bring together some interresting stuff but it can't really compete with the others on their strengths. It doesn't compete well with price of lenses, AF, the variety of lenses or even manual focussing experience (no mirrorless).
It compete if you love the old FAltds, if you love the Pentax ergonomics, pixel shift, IBIS and astrotracer. And most of it was really a differentiator 5 years ago. Now the competition Panasonic, Olympus & Sony have most of it too.