Gwenom, Remorseless Want to play a Bolas' Citadel that isn't a game changer
By playing this card early in the game you have the opportunity to slam your creatures without fearing your opponent playing board wipes
This isn't once per turn either, allowing for multiple counters to be put on it in a turn
Prices fluctuate by a few dollars in each direction, but I havent seen huge sways between sources that actually have stock
Another fun Fluctuator win might be to empty your deck, drop Laboratory Maniac from your hand, and then cycle to win
Filigree Familiar looks primarily like a creature to sacrifice to Elder Deep-Fiend, Wretched Gryff, or Distended Mindbender, but I could also imagine people wanting a speed bump early or just wanting an extra artifact for some kind of artifact synergies