If you go through these and then use a list to draft high stat value minions you should pretty easily be able to get at least 4-5 wins or so each arena run, which will net you 100-120+ gold: https://www.youtube.com/playlist?list=PLvEIxIeBRKSjprrvlbAcbVjzHsnH9PjDXI meant how do you guys play Arena so often, as getting gold to unlock its quite slow, unless you guys spend 1.5 euros every time.
I'd suggest making sure you draft lots of high value 2-3 drops so you can assure you have a good early game, keep a healthy number of 4 drops, and then ensure you have at least a few finishers and later game minions. Removal and board clears are also very good as long as they're sufficiently efficient.
If you get to 7 you get all your money back and can play again for free effectively.
From dailies you get 40 or 60 gold, and every 3 wins in Play mode is another 10, so you can play a ton of arena if you get to a more stable foundation.
But basically ensure you're good at the fundamentals of the game outside of any grand strategy that a pre-constructed deck might have and you should be able to go pretty far.