In reply to kevin stephens:
Really, flying is the only sensible way unless you have at least 3 weeks, and/or very much like driving instead of climbing. The North Sea ferries are extortionate too.
Things have improved in last couple of years due to Norwegian.no, the budget Norwegian airline servicing the north. You can fly them from Stansted to Oslo, then on to Bodo (Ferry to Svolvaer) - or to Harstad/Narvik (Rent a car, then 2 hours leisurely drive to Svolvaer). If you want to go to Stetind as well, this latter is a good option. Looks like about £160 return next July atm.
http://www.norwegian.no/sw7127.asp
Otherwise it's SAS/Wideroe all the way - which is £300+ but takes you right into Svolvaer.
Car hire is expensive but shop around. You can manage without for a week in the Henningsvaer area, but may get itchy feet thereafter. On the plus side, camping is free and supermarket food pefectly reasonable.