We recently returned from a week in the Netherlands and wanted to share that we found buying the temporary Museumkaart a good deal. The Museumkaart costs 75 euros and can be used for 5 museum visits. We used it to visit the Rijksmuseum, the Resistance Museum and the Marine Museum in Amsterdam, the Zuiderzee museum in Enkhuizen, and the Hortus Botanicus in Leiden, all of which purchased separately would have cost 95.5 euros. So as a couple, buying two, we saved 41 Euros. We would have saved even more if the Mauritshuis had been open during our stay, since its admission is 21 euros and we would have used it for that rather than the cheaper Hortus Botanicus, only 13.5 euros admission.
Before our trip I ordered a time slot at the Rijksmuseum for our first morning, selecting Museumcard as the ticket option. Arriving at the museum, we showed the entry person our time slot confirmation and said we needed to purchase the Museumkaart. He pointed us to the ticket counter and they sold us the two cards, scanning them so the Rijksmuseum counted as the first visit.
This website explains the card in English https://www.museum.nl/en/museumpass and in particular the FAQ page explains what the temporary Museumkaart is (it’s a paper card, you don’t need to register it, etc.)
Also—we ended our trip with two nights in Leiden. The last day we had planned to visit the Kinderdijk, but we were tired of bus/tram/train trips and decided to spend the day in Leiden. What a delight! Leiden turned out to be my favorite city out of all we visited. Because it was a Monday, all the museums were closed so we were forced (fortunately) to just enjoy ourselves outside. We had glorious weather and started off at the Hortus botanical garden. Even in September, the garden was beautiful. Then we wandered all over Leiden and were mesmerized by its beautiful canals, so much greenery, and bridges and alleys that went every which way. We walked through the university campus and envied the students lolling in the sun beside the canals. It reminded me of wandering through Venice. We ended the night admiring the lights shining on the canal waters, and hearing a choir rehearsing something wonderful inside an old church. Gorgeous!