This eases my mind a bit, but yeah I’m afraid that paying high kaution and staying in an apartment for years means that the money is just losing a lot of value. 4500e is insane amount of money to just put away but the rental market is what it is. This answered my question, Danke sehr!
Danke sehr! This was really useful, checking the translated word for deposit interest rate led me to check on AT National bank what is considered “industry standard” interest rate (Sparzinsen Entwicklung) and seems about right, normal saving account rates.