A mox start lets you build up a surge of mana and unleash powerful spells before your opponent has the option of mounting a defense - not counting all the other snazzy things you can trigger by casting an artifact
This seems like one of the better cards in white
Cheer Whenever one or more creatures you control with counters on them deal combat damage to a player, you may draw a card and proliferate
Mirage, 1996: $1,908 Mirage is pretty deep, with lots of unreprinted cards holding in around $2, like Kukemssa Pirates and Mangara's Tome
Loxi: This can generate a ton of stats really quickly - since it also hits itself, it realistically can make 3/3 of stats from tapping once if you have two other targets, which is quite a lot for something you can casually drop for 3 mana
The Master of Keys Anyone make this thing work yet