I live in Slovenia and I can give you a hint about how much a meal costs in
this country. I presume you will have breakfast in your hotel and then
search for a restaurant or an inn according to your own heart's desire. A
lunch or dinner should cost somewhere between 14 to 22 US dollars for two
persons. I checked some well known places here in my town (and around it)
with decent food. It should be representative for the rest of the country.
Namely - I live on the border Slovenia/Italy where many Italians come here
to enjoy food in Slovenian inns and restaurants (even on daily basis!). You
probably know how good and demanding eaters Italian visitors are.
I hope this answers your question at least to some extent. If you need more
information or more specific ones feel free to email me. If I don't know the
answer right away I may ask around and let you know then.