Estimated registration cost is 700 euro including accommodation, lunch, and dinner.
The closest airport to Abisko is Kiruna, there are regular flights between Kiruna and Stockholm: http://www.swedavia.com/kiruna/flightinformation/timetable/
Shuttle service between Abisko and Kiruna Airport can be booked through STF (Swedish Tourist association): http://www.svenskaturistforeningen.se/en/Discover-Sweden/Facilities-and-activities/Lappland/Fjallstationer/STF-Mountain-station-Abisko/See-and-do/Transports/Transfer-between-Abisko-and-Kiruna/. They have shuttle buses adapted to arriving and departing flights around lunch. Cost 400Kr/person (40 euro).
There is also buses from the airport directly to Abisko Ö (1.5h). Time table (for bus 91) can be found here: http://www.ltnbd.se/timetables/61/0/
Abisko may also be reached by train from Stockholm. See this website for details: http://www.sj.se/start/startpage/index.form?l=en