Heroic Edition
The digital Heroic edition is now the standard edition (lowest price) but comes with a few items. It costs, $39.99. If you already have GW2 there is no upgrade available to the heroic edition. You can however upgrade to the deluxe edition via the gem store and get the items that come with the digital deluxe edition. The cost to do so is 2000 gems.
Here is the list of what comes with each edition.
http://buy.guildwars2.com/store/gw2/en_US/html/pbPage.buyguildwars2
You can get Deluxe Edition upgrade from gem store for 2000 gems.
As for heroic edition, you can get Legacy armors from gem store for 500 gems each armor weight. You can make your own Mithril Box for 2 gold plus crafting materials. 10 Experience Boosters is useless if you are already level 80.