Flights Stockholm- Kiruna
www.flysas.com - Look for youth prices, you need to log in but it is big discount (26 years and below)
www.norwegian.com - Look for low budget prices
Train Gothenburg/Stockholm - Kiruna
Alternative: Flight Stockholm - Luleå, then with train from Luleå - Kiruna. In case there are no available seats on the flights to Kiruna.
Trains that fit with the winter tours schedule:
Arrival time in Kiruna: 09:15
Departure from Kiruna: 14:44 and 18:32