A major screen debut reprices a character's whole catalogue. Doctor Doom's MCU arrival is the textbook setup — here is the pattern, and the order to buy in.
The pattern is as reliable as anything in collecting: a beloved character gets a major screen moment, search interest explodes, and the collectables reprice — first the key books, then the statues, then everything. It happened to Moon Knight, to Loki, and to every Spider-variant the films touch.
Doctor Doom is the current textbook case. He is the anchor villain of the next Avengers films, played by the MCU's biggest returning star, and his catalogue has been comparatively sleepy for a Fantastic Four character of his stature. Fantastic Four #5 will never be cheap — but the second tier (early FF Doom covers, throne statues, quality masks) is where the wave lands last.
The order matters: buy the books first (they move first and correct hardest), the centerpiece statue or mask second, and let the starter-tier merchandise come to you — it gets discounted after the premiere, not before. The Doom shrine's shelves are arranged in exactly that order of urgency.