Miraidon [Holo] #121 (Pokemon Temporal Forces | Pokemon Cards) prices are based on the historic sales
It doesnt stop there, making your spells cheaper to cast and dealing extra damage
Once your end step begins, it's too late to make a card leave your graveyard in order to cause this ability to trigger

The reconstructed commons sheet for the 1st Edition/Unlimited variant is as follows (the dagger marks indicate that it is not known where the sheet begins or ends): Kabuto, Caterpie, Poliwag, Unown O, Teddiursa, Wooper, Omanyte, Hoppip, Sentret, Unown E, Larvitar, Pineco, Unown I, Dunsparce, Mareep, Spinarak, Energy Ark, Natu, Weedle, Tyrogue, Poliwag, Caterpie, Kabuto, Wooper, Teddiursa, Unown O, Sentret, Hoppip, Omanyte, Larvitar, Unown E, Energy Ark, Unown I, Pineco, Dunsparce, Weedle, Mareep, Tyrogue, Spinarak, Poliwag, Kabuto, Caterpie, Natu, Omanyte, Teddiursa, Wooper, Unown O, Larvitar, Sentret, Unown E, Hoppip, Unown I, Energy Ark, Pineco, Dunsparce, Mareep, Weedle, Tyrogue, Spinarak, Kabuto, Poliwag, Caterpie, Natu, Teddiursa, Omanyte, Wooper, Unown O, Sentret, Larvitar, Unown E, Hoppip, Dunsparce, Energy Ark, Unown I, Spinarak, Pineco, Mareep, Tyrogue, Kabuto, Weedle, Caterpie, Natu, Poliwag, Unown O, Omanyte, Teddiursa, Hoppip, Wooper, Sentret, Larvitar, Unown E, Energy Ark, Pineco, Unown I, Dunsparce, Weedle, Tyrogue, Mareep, Spinarak, Poliwag, Caterpie, Kabuto, Natu, Omanyte, Wooper, Teddiursa, Unown O, Larvitar, Unown E, Sentret, Hoppip, Caterpie, Dunsparce, Unown I, Pineco, Energy Ark, Spinarak, Mareep, Tyrogue, Weedle, Natu The raw data for the holos is as follows (the dashed line is where the transition from H7 to H6 would occur, assuming all boxes in the sample used the same holos sheet

It's a fun and versatile mechanic, and it probably has some sweet applications we haven't even thought of yet
In singleton formats that counts for quite a lot