I went above 1k early on for the achievement of doing so, for the 50,000 gold. Like you, it was a nightmare so I dropped down. I can confirm at least for myself it was exactly 10 in a row, but it took me like 20ish as well because after like 4 someone would just quit right away and reset my counter, which is what probably happens to people saying it took 20 losses.
There's two kinds of tournaments, alternating each day. There's jackpot tournament, which is free to enter. When you play a jackpot game, you have a seperate elo, starting at 0 that's only for that day's jackpot tournament. You are matched up against other people based only on your tournament elo for the day. The games are normal duels, with the only difference is after the game, 80% of your gold earned from the match is instead put in the "pot". After the jackpot ends, the pot is divided among tiers. Tier 1 gets a huge amount of gold, on average something like 65,000? Tier 2 gets less, etc down to tier 5. If your deck is strong, you can make ok gold, but if you don't win lots, it's a total waste to play in jackpot because all you will end up is an 80% penalty on your earned gold for the day and nothing from the pot. Another stupid point is that games played in jackpot ALSO fluctuate your actual elo, so if you're trying to stay under 1k, and get matched against a 1600 player during the jackpot and happen to win due to dumb luck or insane draw, you will gain like 200 real elo.
The other tournament is Swiss. Swiss tournaments require a ticket to enter. Swiss will queue up 8 players together, then there's 3 rounds of games. If you go 3-0, you win the swiss, which gives a free premium pack of the latest expansion. Second place gets a normal pack of the latest expansion. Then, of the 6 other players that lost, 1 emelio pack is randomly given out, but to qualify you have to have played all 3 games without dropping out. There's also one time achievements for lots of prizes for your first time winning swisses. Each faction has a unique hero you get for your first swiss win (such as Shalan for sanctuary, wtb), and a bunch of gold for your first ever win. Finally, one other difference is games in Swiss have a timer of 7 minutes. During your turn your 7 minute timer is ticking down, and during your opponents turn, their 7 minute timer is ticking down. If one of your timers runs out, you instantly lose the match. So you need to be able to play fast, and very slow stall decks are usually less viable as a result.
Now, because Swiss wins are the absolute best source of wildcards, the best of the best players farm them frequently, and if your deck can't beat things like Spell Kelthor, Ishuma rush, Hakeem mill, Dhamria control, Sandalphon lock, etc, it's usually not worth bothering with swiss. You do still at worst have a 1/6 chance per tournament for a free emelio pack even if you go 0-3, but meh. Because the contestants in swiss are just first come first serve, unrelated to elo, you do sometimes get 8 players that are all not top tier, and you can win. I've won a swiss tournament once, and both early games were against clearly newer players, and the final round I was playing Adar vs a crag hack rush, which I was heavily favored to win, even though the crag was a 1600 player. Here's the replay of the final game if you're interested:
Replay :: Sinzar vs Delmar_v | MMDoC King
A final point:
No real reason to save gold when you consider this.
In base set 2, packs will only contain legal cards from base set 2. So, if you plan on swapping to standard format, you will get more value to save gold and buy post-patch, since packs bought pre-patch will contain half or more of cards that are being banned in standard format.