The difference being that Masterwork Chests have a higher probability of dropping certain items, and thus cost more money. ... Assuming you don't want to spend any money on these chests and just prefer to earn them by playing, you may want to keep your behaviour history positive.
What does a masterwork chest give you?
Masterwork chest is a part of Hextech crafting. Once opened, it rewards players with exclusive content. They are the best chest you can get in the game, as they will always contain something that can be bought exclusively with RP. There are several ways to acquire them, both for free and by spending money.
Can masterwork chests give prestige Skins?
Prestige skins can either be unlocked with Prestige Points or acquired with event tokens during specific events. Players can't get Prestige Skins from Chests, but they can obtain Prestige Points from Masterwork Chests.