As someone who has played Hearthstone beta quite a lot, I can tell you right off the bat it is not so easy to get 1600 Arcane Dust the old-fashion way.
As you win games, you obtain gold either by winning three games (10 gold reward) or by completing quests (usually 40-60 gold). With the 100 gold you can buy individual card packs; or with 150 gold you can buy a pass to the Arena Mode gameplay; and if you already have some card duplicates the Crafting Mode button will pop an Arcane Dust Jar to alert you there are duplicate cards that need to be disenchanted.
In Arena, you get rewarded Arcane Dust, gold and cards, so it is recommended to play Arena Mode to collect as much Arcane Dust as possible.
Better Arcane Dust for your Buck
I did never play a TCG/CCG game ever, and don’t know the rules. I’ll mention it as often as I am able. When I first started playing Hearthstone a few months ago, I went with buying single packs of cards for 100 gold each. The results weren’t so great, but I did get a few nice cards.
After the character wipe patch, I have focused my gold spending on Arena-mode gameplay to get my new cards. Alright, an Arena Mode costs 150 gold, and you might not win many games; but this is the way to go to get better cards, and to collect your way to the 1600 Arcane Dust you need to craft the uber card you want. So this is a time investment that will eventually pay off.
Just a few minutes ago, I played Arena Mode two times. Won only 2 games each run. On my third Arena Mode run I won 4 times.
In this attempt, I got one rare, one epic and ta-da! … one Legendary golden card: King Mukla.
King Mukla costs 3 mana to play in a match and he has 5 damage and 5 health. His Battlecry is to give your opponent two bananas. However, the opponent can use each banana to add +1/1 to a selected minion. I don’t like King Mukla much. So I disenchanted it to obtain Arcane Dust toward the card I do want to craft.
When you obtain a Legendary Card that doesn’t have much appeal to you, go to the Crafting Mode browse through the card book and locate the Legendary Card. Right-click it and the Disenchant UI pops up. Click the Disenchant button and you will get 400 Arcane Dust for a Legendary Card. A rare Golden Legendary card provides 1600 Arcane Dust. According to Colorhammer and Eswift in the comments it is extremely rare to find a Golden Legendary card, so you might have to disenchant about 4 Legendary Cards to obtain 1600 Arcane Dust (400 Arcane Dust x 4 Legendary cards). Thanks for the correction.
In my case, I entered Crafting Mode again, clicked the (7+ mana) icon at the bottom to locate Ragnaros, the Firelord. Personally, I like this card a lot. It was used against me so many times, I tested its effectiveness.
It requires 8 mana. Usually by this eighth round most Hex/Sheep/Kill Command/Assassinate (etc.) have been used. If you are lucky, this card will put your opponent in serious trouble. The card itself can’t melee attack. However, at the end of your turn it will hurl an 8-damage fireball at a random enemy minion or at the enemy hero.
If the opponent throws a silence on your Ragnaros, the “Can’t Attack” rule is dismissed. In that eventuality, Ragnaros can melee attack and still kick some booty.
If you aren’t into buying cards for real money, then I recommend spending your gold efficiently in running the Arena Mode. Increase your chances to acquire Legendary cards this way, or other rarity cards and amass those 1600 Arcane Dust. It’s your best shot at crafting your desired card.
If you haven’t seen how Crafting and Disenchanting works, check out my recent article to view the UI screenshots.