I like all three of the suggested solutions. This way players who are spending real money or trading in-game gold for gems still have a guaranteed solution to get the Quaggan mini-pet or at least the gem store only minis.
While people are more than willing to spend money to support this game they love, they shouldn’t have to spend more than the initial game value ($60) on a marginally slim chance to get this one or four minis. Instead of getting 10 people to spend $10 on a set of boxes, they could get 20 people to spend (for example) $10 of money to get the items they want.
They would definitely get the 20 people’s money without leaving a sour taste in their mouth over gambling real money or hard-earned gold (when converted into gems).