this is actually not a question but a suggestion.
With the IKEA Family Card (available for free in all the IKEA stores in your country) you'll have a 3x2 discount on the 3-day Stockholm card, meaning you'll pay the 3-day card for a price of a 2 -day card, saving 145 SEK.
Actually you don't need the IKEA card when you book and pay but I guess they will ask when you go get it, I'll let you know in a week or so.
The Discount Code for this promotion is IKEA and it's valid until September 2014.
Hope this will be useful.