The most valuable Venusaur cards typically include 1st Edition holographic cards from early sets, Gold Star variants, Alt Art cards from modern sets, and promotional cards with limited distribution
That means if you can clone one of your nastiest Myr, or even Brudiclad himself, you can make a token army of them
Choco, Seeker of Paradise rewards you simply for declaring attacks with Birds: even if those 1/1 flyers get blocked or dont deal damage, you still look at that many cards and gain value
As a rather insignificant 1/1, Lady sun can be tapped to return itself and another target creature to its owner's hand
Not every misprint is valuable, but the rare ones that collectors recognize and chase can carry a real premium over their standard counterparts