Hotels are generally in the $40-100/night range. Apartments will be $30-50/night or $300-500/month if you are renting long-term. An average decent apartment sells for $40-70 as of summer 2013.
IN SOME AREAS OF KOLA, EG. KOVDOR, IT IS APPARENTLY STILL POSSIBLE TO BUY A LIVABLE APARTMENT FOR $10-20 TH. AND THERE STILL ARE GHOST TOWNS OUT THERE WHERE THEY CAN BE RENTED FOR THE COST OF TAXES/UTILITIES, AND BOUGHT FOR NEXT TO NOTHING.
Properly equipped heated secured industrial space in Kandalaksha is $20 per square meter per month although a garage can be rented for less, eg. $100-200/month.
Putting up a tent remains free just abut anywhere, no limitations EXCEPT IN THE WOODS DURING THE FIRE SEASON. Also check AREAS PROHIBITED TO FOREIGNERS.