Hi @Timea Fekete - Welcome to Community! :)
Not much details, but yes you can install JIRA on a virtual environment. The cost is different based on what version of application and server you would like to have. To this cost you need to add buying a JIRA license that depends on the number of users you would like to have (https://www.atlassian.com/software/jira/pricing?tab=self-hosted)
There are sites that compare VPS provides in Romania including what hardware they are offering (http://www.uncensoredhosting.com/best-romanian-vps-providers/). Maybe you can start with that information.
A combination of both is to buy JIRA Cloud. You do not need to worry about infrastructure or license. You just pay for every user and have always up to day software. You can find a cost calculator (and all details) here:
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