Hi Sean,
I've published this many times before so if you do a search on Croatia you're bound to find some of my replies.
Accomodation in Croatia is cheap if you're prepared to arrive in a town and take what the little old ladies are offering at the port or bus station. They're usually clean, tidy rooms with a bathroom and very friendly... and they're cheap. Don't be nervous of having a look at the rooms on offer, if you don't like it you just say so, no harm done, believe me.
I've been doing this for years now and have only once in Split had to leave a place, but that was because a night club next door was playing really crap music all night; good music I might have stayed...
I've never had a problem with food in Croatia either, wheter it's buying in a market or a small backstreet cafe. You'll have roast meats of all types, fresh vegetables and fruit and delicious home-made wines and grappa, all pretty cheap too.
Visit Hvar island, and any of the other islands that take your fancy. If a ferry is leaving and you're close by just try it out.... why not, they're all beautiful.
Hope this is some help. If you've got some specific question you can mail me directly. I live in Ireland and might be able to advise you by phone if need be.
But make sure you enjoy planning to travel in Croatia, you won't be disappointed.