Great little camera. Most common things to check are:
lens (for haze, fungus, signs of separation)
lens mount (wobble)
shutter (for operation, oil on blades)
meter (working, reasonably accurate)
battery compartment (corrosion)
flash (does hot shoe work)
battery check light (these often seem to go bad even if meter is working fine, so not a big deal)
light seals (probably bad unless they've been replaced)
controls, especially those little slide controls on the lens (move smoothly)
cleanliness (if there's a lot of dust/dirt inside, I'd be concerned about dust/dirt in the shutter)
film advance and rewind (is it smooth)
self timer (working)
Twice I've seen shutters on these cameras work fine then lock up when the self timer is used. So my feeling is that if the camera is otherwise fine and you don't plan to use the self timer, leave it alone.
Price is very "situational" - based on condition, location, supply and demand at time of purchase. It seems sometimes that prices on these somewhat "cult" cameras rise and fall periodically. I'd say here (in the US) $40-80; so approximately 30-50 euros. I'd add about 10 euros for the matching Canolite flash.