2 packs: We had 2 pack rewards 3 times, only in 9 win runs, out of 15 times. So, we had a 1/5 chance of getting 2 packs when winning 9 times. But it doesn't seem to be an advantage, as you lose about 100 in gold and/or dust.
Golden common: We had golden common card reward in 6 opportunities out of 63 times. Looks like it may happen in all victory scenarios. It gives us around 10% chance of getting it each Arena run, or 2% for each prize (that is just the same for packs, 2% for each card).
Couldn't find a connection between gold and dust but it appears that you get proportionally more gold as the number of wins grows up (until 4 wins you get in average the same amount of gold and dust, after that, you get more gold).
Conclusions by Gantonaci
gantonaci has made a very nice work on the data (original post #96, page 7). His conclusions next:
Crates first roll to see if they contain gold, arcane dust, golden card or pack. After that the amount of gold or dust of each crate is rolled independently.
It may be that first crates roll for crate of little gold, crate of lots of gold, etc. and then when rolling for the amount these different crates would have different probabilities. However to test this hypothesis we would need much more data. So, for now, I'm assuming a simpler model.
For 7 wins, 2 crates will always contain 75G. The other 2 are random. For 8 wins 2 crates will always contain 75G+ and the other 2 are random. For 9 wins 1 crate will always contain 150G and the other 3 are random.
I'm assuming we can get more than 1 golden card or more than 2 packs. Since probabilities are really small we will not be sure of this for a long time.
FWIW, there are 10 ranks of keys (you have to click the image in the posts to actually see the whole thing; for some reason they cut it to only show 6), and you go up a rank with each win. Anything 8 or higher (7+ wins) will guarantee enough gold to re-buy into another Arena run.
Since card packs cost 100 gold each (client strings), and Blizzard said they changed arena entry to be equal to the price of 3 card packs instead of card packs themselves, it is a reasonable assumption that the Area will cost 300 gold to enter.
Your arena information is a little outdated though.
No where has Blizzard said the maximum amount of packs you'd get is 30 if you got all the way to Grand Master.
The maximum amount of wins you can obtain now is 9 before you are forced to end your Arena trip.
There are 10 keys in total, not 6. You always start out with a key and for each victory you will gain another one.
This is a pretty good post to review to get updated on the arena.
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@Fluxflashor - HearthPwn Community Manager Possibly a Mage Player
Yeah, I think so too, and with the arena fee being 150 gold, it's pretty much a no brainer to me, to always play the Arena instead of purchasing packs, as you get back some of the added 50 gold, and it's so much fun.
Reviewing Ezm0d's replay I see that he scored another 9/2 arena. This time he earned 150 gold, with 95, 60 and 55 arcane dust with a booster pack on top.
Also, for the Blizz stream they went 1/1, they didn't lose all of them.
Have to agree that spending gold for the arena seems like the much more interesting option than using it purely for packs. Aside from possibly the first packs, all my gold will be funneled into the arena.
I did a run last night with my first one's free drug deal, err, Arena entry. Went 5-3 and ended up with 1 booster pack, 1 x 50 arcane dust, 2 x 25 and 1 x 5 gold. Oddly it took a long time for the dust to show up in my collection. The booster was the third one I'd opened, and while the first two contained only the standard 4 commons and 1 rare, the pack I got from the arena contained 2 commons (Questing Adventurer and Wrath), 2 rares (Divine Favor and Nourish), and an epic (Sea Giant).
Ended the day with 340 gold so I'll be making another Arena run soon. It's either spend 100g on a booster or spend 50g more for a booster and an arena run.
Second round not as good, 2-3 with a terrible deck. 1 booster, 1 x 5 and 1 x 10 gold, 1 x 5 and 1 x 20 arcane dust. Also in the tally above it should be a total of 55 gold, 50 dust, and a booster pack for my 5 win round