They are found in less than 1% of Collector Boosters, infrequent enough that they do not impact the drop rates for other treatments
This card is crucial in all the Amethyst/Ruby Control decks and also appears in Ruby/Sapphire "Pawpsicle" decks as well
None of the cards included offer any real monetary value, but there is a code included to get both decks in Magic: The Gathering Arena for you and a friend
As far as commons, you'll open an average of 2.37 of each from a box of Ultimate Masters , so even though there aren't any high-value commons in the set (apart from maybe Kodama's Reach, which is over $1 thanks to being a Commander staple), the fact that you get so many commons in a box helps to drive up the value
Ishkanah, Grafwidow Ishkanah, Grafwidow is a really strong spider to have by your side, especially if youre able to get a lot of spider tokens through an Arachnogenesis