Did you notice that older machines have cheaper licences too?
I'm using MorphOS machines as main daily computers. Compatibility with system friendly software is pretty good, but not perfect. Most newer software and especially MUI software should work just fine. Hardware hitting games/demos don't work as said, because MorphOS only emulates the CPU, not the other chipsets, but those which use AHI and RTG are likely to work.
68k software I still use are for example Magellan2, DCTelnet, BackUp, fxPaint2, PPaint, ArtEffect, ImageFX, Photogenics, TVPaint, PageStream, FinalWriter, AmigaWriter, VirusZ, TurboCalc etc.. and lots of 68k shell commands, libraries, datatypes etc. And many good old 68k programs have MorphOS ports (and unless them they'd still work as 68k versions), like CEd, SimpleMail, AmIRC, etc. For many other (internet, cd-burning, imageviewing/processing, audio, movie etc) there are better more recent options natively for MorphOS although 68k counterparts would still work too.
I guess a good starting point to find the info and the stuff would be the MorphOS Library
, and Papiosaur's playlist
for some videos.