Been there early July 2019 and checked the whole vinyl stock. Their records are listed on discogs and there you will also find the prices I was told. Only electronic music (Techno and House). Not really any surprises for me, so I didn't buy anything.
If you're into newer Techno maybe you'll find something. Probably a good source for locals particularly into that sound (cause there's no other store carrying electronic music in town as far as I could figure out).
They also have 2nd hand clothing. The records are in the basement.
If you combine a visit with going through the other record stores in Ljubljana also, rather rent a bike or take a cab cause this one's a bit further away from where the others are located.
It was really not easy to find for me. My mobile navigation took anywhere but there. It's a really tiny store near the Metelkova autonomous center, where I've been taken to first (in case that might help since the store itself doesn't seem to have a google entry so far).