If you book on SAS-sites, you can click "Show eurobonus points (vis Eurobonus-point)" below the total price and tax breakdown on the right side of the booking page. So you know how many points you will get, also booking classes.
If this doesn't work (this function sometimes doesn't work), you can click the ticket type, for example economy flexible, beside the travel dates under Price and Info on the right side of the booking page. Then you click "show fare rules" on the dialogue box. So you can see the whole ticket rules, and the booking class will be there too. But this might be a bit complicated..