Haug's no. 2 was available on an Aurora (or possibly Simax, not quite sure without checking) CD that I'm pretty sure is out of print but that still occasionally shows up on Amazon, albeit at generally inflated prices, or maybe even e-bay. I managed to snag a copy on amazon.de or.uk within the past year or so at a not too outrageous price, but I can't find any current listings. It also used to be available as a download at some Norwegian site that I can no longer find.
The publisher has this CD for sale:
http://nb.bibits.no/wsRecInfo.asp?idno=57268&UnitId=0&DocGrp=0&SearchUnitId=0&LoanUnitId=1&comb=AND&sString=FO=haug,%20halvorAND%20TITLE_DOCUMENT_GROUP_ID=3AND%20searchUnitId0&page=2&language=EngIn fact, all symphonies (including No. 5) are available on CD from the publisher.