Ivysaur is the in-between — the stage you evolve through on the way to Venusaur. That middle-child status kept its 21 cards inexpensive for years, and that's exactly what makes a few of them quietly interesting today.
The story of the line. Because Ivysaur rarely gets the flashy treatment reserved for basics and final forms, its value sits in two places: scarce older promos and the occasional standout modern art card. The Scarlet & Violet 151 #167 Illustration Rare tops the verified list at about $50 raw, followed by the unusual Southern Islands #5 (~$41) — from the dreamy tropical collection with art unlike anything in the main series — and the scarce Dark Ivysaur from the Best of Game promo (~$39).
The grail. Ivysaur's true trophy is vintage rather than modern. The 1999 Base Set Ivysaur in 1st Edition Shadowless — the very first Ivysaur ever printed — is cheap raw but climbs sharply when graded: a PSA 10 has sold for roughly $2,800, many times the unlimited version. For a "middle" Pokémon, that's a serious vintage cornerstone.
What drives value and how to collect. This is a completionist's dream line — you can own nearly every Ivysaur for the price of a single graded grail. The value lives in two narrow places: high-grade vintage (where grading pays off) and a couple of scarce promos. Everything else is affordable set-completion material. If you're chasing highlights, the 151 art card and the Southern Islands promo tell the story; if you're chasing value, focus on a gem-mint vintage copy.