You only get prints up to 20 x 30 cm? Then the K5 you currently already own has better definition than you need.
I've had good 40 x 60 cm prints from my K5 when using decent lenses, and some at 50 x 75 cm that look pretty good too, so you are not yet using the K5 to its full potential.
Or, if you have the funds, get a K1 and continue with your 20 x 30 cm prints whilst owning a camera body that should allow you to get decent 50 x 75 cm prints, and probably much larger, when used with a decent lens.
If you stick with 20 x 30 cm prints. I'd keep the K5 and spend the money on decent lenses.
Last edited by Chester UK; 10-09-2019 at 12:32 PM.
Reason: missing word