What pet did you buy though? Is it demonic hound? Or demonic pets? Angelic pets? Maybe @Golem knows something about it…he had a lot of knowledge about the game
Idk…but my only suggestion to you is too climb higher floors to get rare pets farming(u might even get eternal pets or legends ones…some need requirements to get one…check codex) but since you buy one with dollars…maybe you get random? Or maybe just depends what the game will give you…
from what I’ve read in the Forums, you can only get Epic or lower Pets in the Shop. the only thing I would spend money in the Pet Shop on is an Angelic or Demonic Skin for a Legend or Eternal Pet to accessorize with a Character Skin.
the only way to get Legend or Eternal Pets is by killing Enslavers and/or finishing the Enslaver Feats.