Hi,
Is going to be a Ketron SD5 vs Korg PA800 as far goes price range, there are several areas that make them very different, the Riff, the sampler option, etc...
I play most in "Tea dances" for many of the Senior Centers that Arizona has, I use also the Tyros2, and for most Foxtrots, I found the Korg patterns more suitable than the Yammis, the Yamaha is more Big Band full brass oriented, I sold the PA60 because I want to update, either I get the SD5 by Ketron or the Korg PA800.
I am glad that Korg keep the user interface very similar, perhaps the screen menus to learn, but not the whole thing.