Looking through its EDHREC page, it's clear that the vast majority of the play it's seeing is for its "lands can tap for any color" effect, rather than its "everything is every color" effect
Like most Magic: The Gathering cards, the value of Fynn, the Fangbearer depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Final Fantasy: Through the Ages)
On the third this is 3 mana 'walker is sitting at three loyalty, which is enough to exile a dork or surveil 2 and give him 4 loyalty
That draw ability will set you back life equal to the number of cards in your hand after the draw, though
The most interesting thing happens when Phantasmal Image, being a Messenger without counters, had been "borrowed" from an opponent