We are 12 adults (11 Thais and 1 Norwegian) going on a 3 month trip to Norway around the 20th this month. All visas arranged already so now only ticket issue left. I have tried to search the web for cheap tickets but so far no luck, as the cheapest alternative I found was with Pakistani Airways at 28'000 baht + tax 3'000..I know the fuel prices has skyrocketed lately but still hoping to find a total price lower than 30'000 baht for a return ticket. Anyone who got a good suggestion on how to find?

It's a little late to be booking that big a group, and since Aeroflot is the only airline that even publishes a discount fare to Oslo that would come in below 30,000 baht inc. tax I think you might be pushing your luck.

(And Aeroflot's fares change in July so there's big problems trying to book a cheap ticket with them online that flies out in June, and back in September...)