With good leather shoes, durability typically falls somewhere between 3 and 5 years with regular use - but it really depends on how often you wear them and how well you take care of them! Clarks are actually pretty solidly made, so your 120 euros weren't a bad investment. If you're wearing the shoes every day, they'll definitely be pretty worn after a year. The good news: a worn-out sole is no reason to throw them away! A cobbler can resole them for you - it usually costs 40-60 euros and your shoes will easily have another 2-3 years of life left in them.
What really matters is more about what the inside looks like and whether the upper leather is still in good condition. If the insole padding is falling apart and the shoes get uncomfortable, a new sole won't help much. But if the leather still looks nice and the sole is just worn thin, I'd definitely go to the cobbler! Personally, I'm a big fan of repairing stuff like that instead of just buying new right away. Plus, broken-in shoes just fit better than new ones!