All the mini-based rewards in the Darkmoon Faire only appear to reward a single mini, regardless of ticket cost or background colour.
I’ve purchased the troop rewards with the blue and gold background, and the leader reward with the gold background, and only received a single mini or star.
For example, on the “gold” troop reward, I purchased a new mini that was not in my collection, the Defias Bandit, and now have a common mini with no stars.
Given the ticket costs and effort required to accumulate them, it does beg the question if this was intentional or a bug?
Note that the gold-based rewards do increase as you pick the more expensive ones (though not linearly), suggesting this is a bug as I would expect the same rules to apply