Do you think it's not realistic to buy an apartment by rental cost? You should be surprised, it is possible in the Czech Republic.
Everything works in the following way: You make a minimum contribution for the apartment to the developer, then live in the apartment and pay the rent during a year, thereby confirming your paying capacity. After the year of the lease, you get a mortgage, which is paid, for the frequent, not higher than the value of the real estate lease.
For example:
You buy real estate worth 100 000 €: Make the first contribution of 3%-3 000 €, after that you pay rent during one year-about €450 a month, and after a year, without undue delay, you get a mortgage-payment from €500 per month (that means, in 15 years, you'll obtain the ownership of the apartment).
If this option if not a good fit for you, there are many other options to get mortgage on other terms.