What updates do you expect beyond mapping updates? City Select is, after all, just cartography data - ie maps. Don't get confused between MapSource (the application for viewing the maps, calculating routes etc) which is effectively free anyway, and the cartography itself.
And remember that you are never forced to update the cartography - new versions of MapSource are free so you stay compatible with new versions of Windows etc. If all the roads you want to use are shown in the cartography that you've got, why waste money on an upgrade?
Of course if you are visiting an area that wasn't mapped in the older version (eg Greece) then that's a good reason to upgrade. But I'm managing just fine with City navigator v5.