A two mana flyer is a great creature to play early in the game as it is likely to get in for a fair amount of damage or eat a removal spell out of an opponent's hand
This card's playability is vastly increased in Advanced format, and it can be of use in almost any deck type that doesn't involve swarming or an emphasis on quickly decreasing the opponent's LP
Outside of Vintage, Tezzeret may still see play in a deck with lots of cheap artifacts and artifact creatures
With thousands of cards being graded, having a clear goal helps you focus your efforts and your budget
Will the Merchants get their goods past the Sheriff? The bustling market in Nottingham is filled with goods from all over the kingdom
The short version is that there's a cap on the value of the cards in a Magic set while it is in print, because if the cards in the set ever end up being worth so much that it's profitable to open a sealed booster box, people will open boxes, increasing supply and driving down prices