Because The Master, Multiplied was only printed in one set (where you could either find it in a $50 Commander precon or in $20-$30 Collector packs), the supply for this card has always been low
One has to concentrate extremely hard to both understand the text and be able to read it
Those ended up too difficult to track or too rewarding for only drafting lands
For example, Complains Clerk has "Whenever you roll a 1, create a 1/1 white Clown Robot artifact creature token." If you choose that ability, you ignore everything up to the first comma, ending up with "Create a 1/1 white Clown Robot artifact creature token." Some triggered abilities have an "intervening if" clausethat is, they are written in the form of "When/Whenever/At [trigger event], if [condition], [effect]." If you choose such an ability with Trigger Happy, you ignore the trigger event, and the ability will go on the stack even if the intervening if condition is not fulfilled, but the ability will still check the intervening if condition as the ability tries to resolve
If you have already performed a data link, you can still clear the mission by opening the data transfer menu
I'm sure there are plenty of people out there who only care about the monetary aspects of it, and I'm sure rarity plays a part - after all, some of these cards will be 30 years old soon and that makes them naturally harder to find
