Price of pint of beer is normally about six quid. No, really.

Sea travel takes about twenty hours and I heard is not that much cheaper than air, but do not know. Hostels cost around twenty quid a night, iirc, not including breakfast which I think is not worth getting.

www.tourist.reykjavik.is is the site.

I think Skaftafell, where I spent most of my time, is pretty much closed in winter out of weather-ness. But it's ways away from Reykjavik anyway.